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True DiversificationA Optimization
Applied to Equity Index Construction
James Damschroder
Founder & Chief of Financial Engineering, Gravity Investments LLC
Jonathan Bower
Associate Director of Financial Engineering, Gravity Investments LLC
This Draft: 11/11/2010
ABSTRACT
Capitalization-weighting is the dominant method of index construction and is
the primary benchmark used for measuring market and manager performance in
the investment industry. Using the components of the S&P 500 Index, we
investigate an alternative process-driven methodology for index construction and
optimization that is centered on True Diversification®. We find that when
reconstituting the S&P 500 universe from January 1996 to July 2010 using our
methodology we can achieve annualized outperformance of 499 bps against the
benchmark index.
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Table of Contents
Section 1 – An Overview .........................................................................................................3
Section 2.1 – True Diversification® Optimization ..................................................................5
Section 2.2 – Settings and Process ...........................................................................................7
Section 3 – Data ........................................................................................................................9
Section 3.2 – Data and Process Exceptions ...........................................................................10
Section 4.1 – Methodology.....................................................................................................12
Section 5 – Analysis Overview ..............................................................................................14
Section 5.1 – Risk and Return Analysis ................................................................................14
Section 5.2 – Factor Analysis .................................................................................................21
Section 5.3 – Investment Analysis .........................................................................................25
Section 5.4 – Allocation Analysis ..........................................................................................30
Section 5.5 – Turnover Analysis ............................................................................................33
Section 6 – Conclusion ...........................................................................................................34
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Section 1 – An Overview
Capitalization-weighted is the dominant method of index construction and is the
primary benchmark used for measuring market and manager performance in the
investment industry. There are several reasons for this choice in methodology
including less trading, low transaction costs, convenience, and large investment
capacityB. These factors have led institutions and managers to invest or benchmark
trillions of dollars in assets to these indices. Much time and effort is expended
attempting to “beat” the benchmark in its current framework, rather than focusing on
inherent structural deficiencies related to capitalization-weighted.
It is our contention that most traditional indices, by being capitalization-weighted,
provide a false sense of security because number of assets in the index is large, implying
good diversification properties. As an example, in the S&P 500, the top ten percent of
the index holdings account for approximately fifty percent of the index’s valueC. While
the S&P 500 or other capitalization-weighted indices may be good proxy for the
“market”, from a portfolio diversification perspective, they are poorly constructed.
Diversification, according to the authors is represented by both minimizing the
exposure of a portfolio to common risk factors (systemic risk) and minimizing the
idiosyncratic risk. No external benchmarks are required, which is an advantage for an
enduring index construction methodology.
Recently within the investment management industry there have been numerous
proposals for alternative methods of creating indices or developing financial products
that indirectly attempt to address the inherent weaknesses in capitalization-weighting.
Examples including GDP-weighted, equal-weight, and Fundamental WeightedD have
been proposed and are now available to investors. At the heart of these efforts is the
(correct) intuition that there is a need to create an index or product that has better
diversification properties.
Rather than address this issue of diversification indirectly we have explicitly created an
index that’s sole focus is on diversification. We believe that True Diversification®
weighting is both unique and superior to those solutions currently available in the
marketplace and importantly is not constrained to a particular market, style, or even
asset class. Also, portfolio diversification based on Gravity Investment’s philosophy
has also been shown to provide material performance improvements to both risk and
returnE. Such findings are herein reconfirmed.
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One of the traditional methods of portfolio optimization and construction is mean-
variance optimization which was pioneered by Harry Markowitz in the 1950’sF. While
Markowitz models and the variants it has spawned have gained significant application
in industry they have not gained significant traction as index construction
methodologies. True Diversification® holds several advantages over mean variance and
other optimization techniques that make it better suited for index construction. Among
these attributes are consistency of time-variant allocations, relative de-sensitivity of
model outputs to small changes in inputs, no requirement to include exogenous risk
profile information to select the correct risk-efficient portfolio, the ability to include
assets with short histories, and total ex post performance.
While Markowitz is a pioneer of diversification, a mean-variance optimization is an
inefficient way to attain it. In mean-variance optimization, diversification is achieved
by combining assets with the objective function of variance minimization. As such,
diversification is inherently subservient to variance minimization. Diversification is
actually sacrificed to produce lower volatility. However, the focus on volatility fails to
exploit an asymmetric diversification/return relationshipG. Furthermore, diversification
is shown to have greater stability in a crisis and has a material impact on performanceH.
One important distinction in our index construction using True Diversification®
optimization is that we do not make any judgments about the universe of inclusions for
an index in the search for improved investment characteristics. Rather our focus is
based solely on the current components within the index and finding a more optimal
allocation of those individual assets within the context of portfolio diversification.
Thus, True Diversification® has the necessary flexibility to be applied across any index
or combinations of indices irrespective of asset class or quantity of investment options.
Our True Diversification® index construction and optimization is systematic and
process-driven. Frequently when one encounters “optimized” anything, especially in
the realm of finance, there is always a concern of data-mining to find the best solution.
As will be outlined in Section 4, there are potentially an infinite number of permutations
in the choice of settings and constraints when performing the optimization routine. For
this research we applied one, and only one, settings and constraint schema across the
approximately 600 portfolios necessary to complete the research. Also, the labor
involved in undertaking the optimization process precluded any attempt at multiple
iterations of this same research applying various settings. We have little doubt that it is
possible to find additional performance benefits by applying a different set of
constraints and/or settings, but we leave that as fertile territory for future research and
development.
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While our primary focus in Section 5 is on the aggregate equity index, we present the
analysis for the ten sector indices and one aggregate index. We present the analysis of
the optimized sector indices in Sections 5.1 and 5.2 to demonstrate the consistency and
robustness of our methodology. In most cases we demonstrate statistically significant
superior investment performance relative to our benchmarks. For a couple of the sector
indices we cannot make the claim of statistical significance in our outperformance;
however, even in such cases, we can demonstrate a level of consistency in performance
that demonstrates that True Diversification® optimization consistently improves the
investment characteristics of an index.
Finally, in Section 6 we summarize our findings and make the case for True
Diversification® optimization and our index construction methodology. We believe the
implications of this research for the investment industry are potentially profound.
Section 2.1 – True Diversification® Optimization
The section provides a brief explanation of True Diversification® Optimization which is
a holistic asset allocation model and visualization platform. The process maps asset
correlations to vector angles and projects them into three dimensions. The vector
lengths in the model define the relative attractiveness of assets based on a utility
function. The model then imposes a convex hull on the asset XYZ point-cloud. Those
assets comprising the convex hull create the efficient set. Any assets that are dominated
by the convex hull are considered inefficient assets. The total portfolio value equals the
volume of the polytope formed by the convex hull. The model gives an optimal asset
allocation by dividing each asset’s pro-rata volume by the polytope volume.
Diversification Optimization models diversification as a trans-dimensional factor. It
represents diversification in every dimension, not in any single dimension. We map
asset relationships in an N-dimensional vector space. The portfolio of asset candidates
is projected to a smaller dimension using our optimization logic. The model equates
correlations (ρ) to the cosines of angles for every asset in the space where:
ρ = 1 maps to a 0 degree separating angles
ρ = 0 maps to 90-degrees separating angles
ρ = -1 maps to 180-degrees separating angles
This relationship can be seen in Exhibit 1 below.
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>>>Insert picture
The model algorithm creates three matrices of equal size where:
C: an estimated correlation matrix, generally derived from historical sample data
A: a matrix of the cosines between vectors graphed in N space
E: a error matrix that gives the difference between C and A
C + E = A
The optimization then begins with a population of XYZ points for all asset candidates
and the fitness function for evaluating the correctness of this population of points is
defined by:
��
����
�
�������
The length of any vector is a utility function that quantifies the relative attractiveness of
any asset. The greater the utility function’s value the longer the vector length. Greater
distances signify that the asset is more likely to extend the shell of the model, dominate
its peers, and capture a greater proportion of volume.
The enclosure imposed on the point-cloud is a convex hull and can be seen in Exhibit 2I.
Whereas mean-variance optimization creates an efficient frontier, the convex hull is
analogous to the frontier, but comprised of only the efficient assets in the portfolio.
Therefore, the convex hull is an efficient frontier of individual assets comprising one
single efficient portfolio. The shape of the hull depicts the balance of the portfolio. This
hull also determines the volume of the model portfolio, which is set equal to the capital
allocated.
>>>Insert picture
True Diversification® Optimization allocates resources based on pro-rata volume. To
determine each region’s volume we first calculate the center of gravity or “centroid” for
the modelJ.
The center of mass is ),,(321
xxxO = . To find its coordinates, xi, we use:
� = ∑���� �.��
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Where N is the number of assets and ji
x,
is an i-th position coordinate of the j-th asset, D
is the portfolios projected dimensionality.
Next, True Diversification® Optimization splits the assets comprising the convex hull
with a bisecting plane. The model creates a facet with an asset as the vertex and all of
the adjacent bisecting planes. This facet connects to the model centroid to create the
assets’ unique relative volume as illustrated below where:
A, B, C and P are assets
O is the center of mass
ABP and APC are facets of the convex hull
L and N are the centers of the facets
The model calculates the centroid with N=3 and j is a number of the vertex of the
facet OD and OM are the bisecting planes of the BOA and POA angles.
Thus, the bounding bisecting planes are ODL, OLM, OMN, OMK etc.
Finally, the pro-rata volume is calculated. The area of the convex hull is calculated, and
then True Diversification® Optimization calculates the volume for each region (asset)
and determines the ratio of any region relative to the entire polytope volume. This
provides a globally optimal allocation for each asset.
Section 2.2 – Settings and Process
The optimization process described above is embedded in a proprietary software
platform using a patented optimization process. Given that this software was
instrumental in conducting the research we provide an overview of the available inputs,
L
A
B
C D
O
M
N
K
P
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settings, and constraints. The software is highly customizable and allows a user to
apply a series of constraints, settings, and adjustments for constructing and optimizing
a portfolio/index. Each of the sectors and then the composition of those sectors into an
aggregate index had the same settings and constraints applied to them.
The following steps highlight the settings and constraints used in the True
Diversification® index optimization process.
1. Determine the asset universe
The user can input ticker symbols directly or import a collection of ticker
symbols from an Excel spreadsheet.
2. Impose minimum and/or maximum constraints
The user can constrain all or some of the assets in the portfolio based on
allocation percentages, dollar values, or number of shares. This has the
practical benefit of ensuring an allocation consistent with policy
guidelines.
3. Import historical data for assets based on:
a. Time period length
b. Time period frequency
c. Number of samples
d. Weighting of samples
The user can select a historical sample period for the assets in the portfolio
based on daily, weekly, monthly, quarterly, or annual pricing frequency.
The user can also specify multiple samples and has the ability to
independently weight the respective samples. For example a user could
combine a six-month daily sample with a weight of 1 and a five-year
monthly sample with a weight of 2. The relevant return and statistical
calculations are the weighted average of the samples.
4. Statistical adjustment of historical time-series including:
a. Application of James-SteinK shrinkage
b. Selection of risk quantification as denominator to the utility function
c. Selection of correlation matrix
Shrinkage can be applied to the (blended) historical risk or return values
independently and can also be shrunk towards specific values. Risk can be
defined by the standard deviation, semi-variance, or maximum drawdown. All
of the adjustments made to the historical data and the selection of risk
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measurement provide the optimization routine with a utility function, nominally
the Sharpe RatioL, Sortino RatioM, or the Calmar RatioN depending on the
definition of risk. The correlation matrix can be price or returns based or can be
defined by the semi-correlation. The semi-correlation is analogous to semi-
variance in capturing the downside correlation of asset co-movements.
5. Select dimensionality of computation space for optimization
The selection of dimensionality in practice affects the relative breadth of
allocation in a portfolio. Lower dimension calculations result in a more
concentrated portfolio where the better diversifying assets receive higher
allocations at the expense of the marginal diversifier.
Section 3 – Data
One of the core considerations in performing this research was to avoid survivorship
and hindsight bias. Our process is designed to maximize objectivity and avoid all
known bias possibilities. To that extent, every effort was made to ensure that when
performing the optimization of the indices we used only the data that was available up
to that point in time. The software had no visibility to any data looking forward from
the optimization date. Secondly, we wanted a large enough sample to draw statistically
meaningful results and have a sample sufficiently large that we could evaluate our True
Diversification® methodology in a variety of market conditions including the “bull
market” of the late 1990’s and the “lost decade” of the 2000’s. We used three data
sources in an effort to address these issues.
We were provided with quarterly holdings data on the S&P 500 from Standard &
Poor’s. This data gave us a snapshot of the S&P 500 on the first date of each quarter
from Q2 1995 through Q3 2010 and included the date, company name, company ticker
symbol, CUSIP, stock price, shares outstanding, market capitalization, and GICS code.
There were 953 different companies that made up the S&P 500 Index over our sample
period. We believe this data to be accurate and correct but did not cross-check it against
other sources. The only change we made to this dataset was the ticker symbol
conventions to make them compatible with our databases and software as needed.
Much time and effort was expended going through this dataset company by company
to accurately identify and match the corresponding company to the correct historical
data to account for changes in the exchange ticker symbol through time or any
associated M&A activity.
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We used two databases for our historical stock price data. For currently listed stocks we
used a database that we maintain from Thompson-Reuters. We also acquired a delisted
stock database from Norgate Investor Services and integrated it into our database. The
data we used in both instances is split-adjusted but was not adjusted for dividends.
While believe the historical data to be correct and accurate, we did not cross-reference
the data against another database to confirm its validity. However, when conducting
the research we found no obvious errors or omissions in the data save the few
companies we were unable to match to their respective place in the benchmark indices
history.
Section 3.2 – Data and Process Exceptions
Despite our best efforts, there were a few companies that either we could not ascribe to
a particular ticker in our database to or we simply did not have the data for that
company at that time. Given that there are almost 31,000 observations in the S&P
dataset and we are missing approximately 250 data points it is likely that their omission
does not materially affect our results. In instances when a company could not be
correctly identified within our database it had a blank ticker assigned to it and it was
excluded from consideration in the index.
The second consideration with respect to the S&P dataset is that it was provided at a
quarterly frequency. We recognize that the S&P 500 is updated in real-time based on
corporate actions or market conditions and additions or deletions to the index can occur
within a quarter. Our choice of quarterly data was a concession to practicality when it
came to working within the confines of the software and still being true to following a
systematic and process driven index optimization. We believe our choice, while it may
not perfectly match the exact same holding as in the S&P 500 universe at every instance
in time, is true to the spirit of this research.
We did not have specific dividend data and we elected to not incorporate dividends in
our analysis. Therefore, the indices we created are price-based and we selected price-
based benchmarks for use for our comparison and analysis. It is not clear what, if any,
effect or bias may have been introduced in the optimization process by using non-
dividend adjusted price series. The dividend yield on the S&P 500 index for this period
is approximately 1.8%O. The net effect, if any is likely small, but as yet undefined.
We found a few instances where no or limited historical data was available for a
particular asset. This could occur either through a corporate action, missing data or
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specifically M&A where a new company was formed and merited inclusion in the
original index, but had no history directly attributable to the new corporation. The
ideal way to deal with the scenario would be to use the historical data from prior to the
merger associated with the acquirer to calculate the appropriate risk statistics.
However, from a practical stand point this was not a realistic prospect for the research
project. To deal with this situation we assumed zero for risk, return, and correlation
calculations of the asset. Such risk and return inputs would later be normalized, having
the impact negated. The impact on correlations would generally tend to favor such
assets. If the available data if shorter than the specified historical sample period
requested we would use the entirety of available data.
In the case where there was no data available for the subsequent periods to compute a
return. This scenario could be caused by M&A activity where the acquired was no
longer listed or if a bankruptcy occurred or we did not have the data in our database.
In this case we assigned a 0% return for that asset’s allocation within the index. The
ideal way to deal with this situation would be to compute, in the case of a merger, the
allocation to the new company or acquirer and compute that return. In the case of
bankruptcy then a -99% return could be used. Again, as a matter of practicality this was
not a feasible solution when it was encountered. We believe this choice may have
created a slight downward bias in our ex-post return numbers by applying a 0% return,
but we as yet, we have not measured this potential impact.
Finally, a third case where we could have an allocation to an asset but in the following
quarter it is no longer included in the original index but data is available to compute a
return. A scenario that could cause this situation is a company’s market capitalization
declining during the prior period and being removed from the original index. In this
scenario we would still maintain an allocation to the now excluded asset and over time
it would be replaced by newer assets allocations. This is the most prominent deviation
from the original index in that we did not remove the asset until our next reconstitution.
This scenario also biases our results downward. While we have not studied exactly
how much we give-up in performance in this situation, Sui P demonstrates that recent
deletions from an index have significant negative alpha after being dropped from an
index. Also, Sui’s research indicates that recent additions have short-term positive
alpha and in our research and index construction process we have a decidedly negative
asymmetric exposure to these phenomena. That is, we hold our “losers” that dropped
from the index over a negative performing period, yet have proportionally less
available exposure to the “winner” that was added to the index since we are only
applying 25% of the addition’s potential weight by implementing an overlapping
portfolio construction process.
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We think our choices in methodology are broadly intuitive, simple and conservative in
nature, but we cannot definitively state what the potential performance impact is from
these choices vis-à-vis another set of choices with any accuracy.
Section 4 – Methodology
The purpose of this research is to demonstrate that through the application of a
systematic, process-driven application of True Diversification® optimization we can
build an index with superior investment characteristics. We opted for a “building
block” approach where we first optimized each sector, as defined by their GICS
classification, as a stand-alone index. Our hypothesis was that we could compound
outperformance by compounding the optimization process. We took these optimized
sector indices and allocated them based on another layer of True Diversification®
optimization into the aggregate index, the “True Diversification® 500”. This aggregate
index has ostensibly the same components as contained in the S&P 500 through time.
The process for creating the indices was applied systematically and without deviation
for all optimizations and was performed as follows:
1. Collect the ticker symbols that were defined as being in the index we are
optimizing on the first business day of a quarter from the S&P dataset
2. Apply any allocation constraints to the portfolio
3. Import the relevant historical data for each ticker symbol up to the point in time
defined in (1.)
4. Apply any necessary statistical adjustments to historical data
5. Compute the optimization and save the allocation weights
6. Evaluate the obtained weights to the ticker symbols for the subsequent period
(one year)
7. Export the computed returns associated with new portfolio and create a
continuous return time series
8. Repeat this process for each quarter and sector
Applying this process for each index provided us with four time-series outputs with
each one corresponding to the beginning of a quarter and having a one-year holding
period. Each quarter’s one-year holding period return was made into a continuous
time-series. To make them continuous we took the average return on the second day of
the appropriate quarter from the new optimization and the corresponding day from the
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prior optimization. This blended return is what we used as a reasonable approximation
one would get from trading and implementing the new allocation weights on the index
not including the impact of transaction costs, execution, liquidity, or other market
variables. The net result was four time-series for each index that correspond to a set of
returns attributable to the index based on an annual re-optimization and held for one
year from the beginning of Q1, Q2, Q3, or Q4. The following flow chart describes this
process:
1/2/1996 1000000
1/3/1996 1001214 0.12%
1/4/1996 999693 -0.15%
1/5/1996 991899 -0.78% 1/2/1996
. . . . . . . . . . . . 1/3/1996 0.12%
12/31/1996 1133983 -0.73% 1/4/1996 -0.15%
1/2/1997 1124645 -0.82% 1/5/1996 -0.78%
1/3/1997 1137476 1.14% . . . . . . . .
1/6/1997 1132563 -0.43% 12/31/1996 -0.73%
1/7/1997 1137294 0.42% 1/2/1997 -0.82%
1/3/1997 1.14%
1/6/1997 -0.50%
1/2/1997 1000000 1/7/1997 0.80%
1/3/1997 1012851 1.29% 1/8/1997 -0.05%
1/6/1997 1007110 -0.57% 1/9/1997 0.91%
1/7/1997 1015240 0.80%
1/8/1997 1014710 -0.05%
1/9/1997 1023948 0.91%
We chose to create these four time-series for each sector to reduce any bias resulting
from selection of a reconstitution date. Using these sets of time-series allowed us to
evaluate the performance of each index based on all combinations of quarterly, semi-
annual, and annual optimizations and holding periods including the use of both
overlapping and non-overlapping index construction. Across the sectors occasionally
we found that there were some sectors that benefited from a particular holding period
or timing. This most likely is a function of randomness, although we don’t rule out the
potential of a structural element to these findings. In aggregate no single method of
index construction was superior to another and we opted for what we feel is the best
blend of the evaluated methods.
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We selected quarterly overlapping portfolios with one year holding periods as our
method of choice. Selecting this method of index construction means that each quarter
25% of an index is re-optimized and allocated. In many ways we also feel this is an
intuitive selection and does the best job of staying “on benchmark” in terms additions
or deletions of the components in the benchmark indices juxtaposed against the
potential negative effects associated with transaction costs and turnover that could
occur had we selected re-optimizing and allocating an entire index every quarter. We
have included, in the appendix, a table showing risk and return values for each of the
sectors and the True Diversification® 500 for each of the proposed index construction
methods to allow the reader to draw their own conclusions on our decision to
implement our chosen method.
Section 5 – Analysis Overview
The goal of this research was to test the idea that we could systematically apply True
Diversification® optimization to a universe of assets as defined by an index and create a
better performing investment. We have achieved the desired objective. The True
Diversification® 500 was not built to track the benchmark index and it can deviate
substantially from year to year in outperformance or underperformance. Presented
below are a collection of tables and charts that make the case, that not only is our
method superior to the benchmark index from a total return perspective, but it is also a
much more stable investment which is a desirable outcome for all investors. We begin
our analysis with the raw return numbers for all eleven indices (ten sectors and one
aggregate) that were created, followed by a factor analysis using regression to assess the
investment “characteristics” of the indices. In the third portion of the analysis section
we examine the returns of the True Diversification® 500 from an investor’s perspective
and evaluate the index’s consistency. In the next section we examine the sector
weightings used in creating the True Diversification® 500 and point to some interesting
observations about their behavior. Finally, we evaluate the turnover of the True
Diversification® 500 using two different methods. We compare these figures to other
indices and investments and then consider the potential impact of transaction costs for
implementing the True Diversification® 500.
Section 5.1 – Risk and Return Analysis
In this section we examine the basic risk and return statistics for the ten optimized
sector and True Diversification® 500 index and compare them to their respective
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benchmark. We provide this analysis for the sectors to highlight the consistency of our
methodology and True Diversification® optimization. We break these statistics into
three groups. One is the full sample from January 1996 to July 2010 presented in Table
1. The other two tables are sub-samples which report the risk and return statistics for
the late 1990’s “bull market” covering January 1996 through December 1999 in Table 2.
Table 3 presents the other sub-sample which covers the “lost decade” from January
2000 through July 2010. Table 4 presents the monthly returns of the True
Diversification 500 over the full sample period. We draw your attention to several key
facts presented in the first three tables.
First, from a return perspective, all ten optimized sectors beat their respective
benchmark by an average of 3.16% on an annualized basis and ranged from 0.3% to
5.12% in outperformance. The True Diversification® 500 beat its benchmark by 4.99%
on an annualized basis. Secondly, from a risk perspective, the standard deviation of
the ten optimized sectors had volatility that was 0.26% per year higher than their
benchmarks. We consider this to be “good” volatility in that it is upside volatility. We
draw this conclusion because the average sector’s down-side volatility was reduced by
0.19% per year relative to the average benchmark. Examining the maximum drawdown
experienced by each optimized sector we again see an aggregate reduction in
drawdown, with an average reduction in maximum drawdown of 2.65% relative to the
average benchmark. The True Diversification® 500 over this sample had 0.46% less
volatility, 0.92% less downside volatility, and a 3.91% improvement in the maximum
drawdown over the benchmark index.
In the first sub-sample, the “bull market” period, only one of the optimized indices
outperformed their respective benchmark although the optimized indices on average
reduced standard deviation and downside deviation. This is not to say we had negative
returns, rather we point to the True Diversification® 500 which had annualized
performance of 17.84% during this period whereas the benchmark index returned
22.15%. The average sector underperformance during this period was of a similar
magnitude relative to the average benchmark sector, 14.35% versus 18.6% respectively.
Perhaps more important to this section from an analysis perspective are the risk and
return statistics from the “lost decade” of the 2000’s. The average sector had 5.69% in
annualized outperformance and the True Diversification® 500 outperformed by 8.04%.
Again, these returns we achieved with nearly the same or less risk than their
benchmarks.
The performance drop off between the two samples is also worthy of comparison. For
instance the True Diversification® 500 went from a 17.84% annualized return in the
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“bull market” to a 5.82% annualized return during the “lost decade”. This represents a
drop-off in performance of about 12% a year, but still positive in both sub-samples.
Contrast this result to .SPX which had a drop-off in performance of more than 24% and
lost 2.22% on an annualized basis during the “lost decade”. Interestingly, the
performance of the True Diversification® 500 over the full period was 9.06% with a
standard deviation of 15.84%. This is very close to the oft-cited “historical” return of
stocks over the last century of 8% a year with 16% volatility. The traditional benchmark
during the full sample returned less than half that amount.
We believe these results are one way of pointing to the consistency and repeatability of
our True Diversification® optimization. Anecdotally, we have found that when
applying True Diversification® optimization to a portfolio of assets we typically can
improve performance. Our average sector optimized indices added about 300bps in
annualized outperformance relative to their benchmarks. The application of another
layer of True Diversification® optimization when aggregating the sectors into the True
Diversification® 500 added almost another 200bps in performance. We believe that the
performance and stability of the indices from both a risk and return perspective is an
artifact of building these indices using a diversification centric approach to investing.
©2010 Gravity Investments, LLC 17
Duplication or dissemination prohibited without prior written permission.
Table 1: The True Diversification® optimized indices are listed by their sector name and the benchmark GICS sector
is listed by its relevant ticker symbol. We computed the geometrically compounded annualized return for ten the
optimized and benchmark sectors plus the aggregate True Diversification® 500 and its benchmark index for the full
sample period of this study, January 1996 – July 2010, using monthly return values. We also computed the
annualized standard deviation, the semi-variance often referred to as downside deviation, and the maximum
drawdown of the respective index. Each optimized index is matched to its benchmark index and the difference
between the relevant risk and return attributes is computed. We also computed the average of each optimized and
benchmark sector as an additional data point for comparison.
Annualized
Return
Standard
Deviation
Semi-
Variance
Maximum
Drawdown
Consumer Staples 6.58% 12.70% 8.62% 31.69%
.GSPS 5.01% 13.73% 9.34% 31.22%
difference 1.57% -1.04% -0.72% 0.48%
Consumer Discretionary 7.12% 20.44% 13.99% 61.49%
.GSPD 5.20% 19.73% 13.46% 56.24%
difference 1.92% 0.71% 0.54% 5.25%
Energy 12.13% 24.49% 15.69% 59.71%
.GSPE 8.30% 19.78% 12.69% 49.76%
difference 3.83% 4.71% 3.01% 9.94%
Financial 6.72% 22.50% 15.39% 73.95%
.GSPF 1.94% 24.16% 17.42% 80.05%
difference 4.79% -1.66% -2.03% -6.10%
Healthcare 9.51% 14.85% 10.36% 35.58%
.GSPA 5.36% 16.07% 10.97% 39.90%
difference 4.15% -1.21% -0.61% -4.32%
Industrial 4.92% 18.09% 12.60% 50.80%
.GSPI 4.63% 19.22% 13.54% 60.24%
difference 0.30% -1.13% -0.93% -9.44%
Information Technology 8.16% 30.29% 19.83% 72.52%
.GSPT 6.39% 30.08% 20.37% 80.35%
difference 1.77% 0.21% -0.54% -7.84%
Material 7.36% 21.39% 13.98% 50.68%
.GSPM 3.39% 22.20% 14.86% 57.87%
difference 3.97% -0.81% -0.88% -7.19%
Telecommunication 3.62% 25.21% 17.01% 78.24%
.GSPL -1.50% 22.45% 15.75% 76.11%
difference 5.12% 2.76% 1.26% 2.14%
Utilities 5.58% 17.13% 11.41% 49.14%
.GSPU 1.39% 17.03% 12.35% 58.58%
difference 4.19% 0.10% -0.94% -9.44%
Average Sector 7.17% 20.71% 13.89% 56.38%
Average Benchmark 4.01% 20.45% 14.07% 59.03%
difference 3.16% 0.26% -0.19% -2.65%
True Diversification® 500 9.06% 15.84% 10.81% 48.64%
.SPX 4.07% 16.30% 11.73% 52.56%
difference 4.99% -0.46% -0.92% -3.91%
©2010 Gravity Investments, LLC 18
Duplication or dissemination prohibited without prior written permission.
Table 2: The True Diversification® optimized indices are listed by their sector name and the benchmark GICS sector
is listed by its relevant ticker symbol. We computed the geometrically compounded annualized return for ten the
optimized and benchmark sectors plus the aggregate True Diversification® 500 and its benchmark index for the
sample period of this study, January 1996 – December 1999, using monthly return values. We also computed the
annualized standard deviation, the semi-variance often referred to as downside deviation, and the maximum
drawdown of the respective index. Each optimized index is matched to its benchmark index and the difference
between the relevant risk and return attributes is computed. We also computed the average of each optimized and
benchmark sector as an additional data point for comparison.
Annualized
Return
Standard
Deviation
Semi-
Variance
Maximum
Drawdown
Consumer Staples 8.30% 13.05% 8.09% 23.85%
.GSPS 9.03% 17.47% 11.30% 22.27%
difference -0.73% -4.42% -3.21% 1.59%
Consumer Discretionary 12.72% 17.10% 11.85% 20.57%
.GSPD 22.90% 17.28% 10.79% 16.72%
difference -10.17% -0.18% 1.06% 3.85%
Energy 8.42% 21.90% 13.49% 31.73%
.GSPE 13.23% 17.86% 9.48% 20.90%
difference -4.81% 4.04% 4.02% 10.83%
Financial 15.35% 18.94% 12.05% 19.10%
.GSPF 19.63% 22.54% 14.61% 23.24%
difference -4.28% -3.60% -2.56% -4.14%
Healthcare 13.56% 16.65% 11.49% 17.87%
.GSPA 21.82% 19.21% 11.50% 15.33%
difference -8.26% -2.56% -0.01% 2.54%
Industrial 5.38% 16.96% 10.71% 24.55%
.GSPI 15.91% 17.10% 10.71% 20.41%
difference -10.54% -0.14% 0.00% 4.13%
Information Technology 34.68% 26.86% 15.00% 23.86%
.GSPT 50.94% 28.93% 14.04% 16.40%
difference -16.26% -2.08% 0.95% 7.46%
Material -0.07% 22.19% 14.64% 32.94%
.GSPM 4.62% 21.25% 13.16% 26.45%
difference -4.70% 0.94% 1.48% 6.50%
Telecommunication 34.71% 19.07% 9.49% 11.74%
.GSPL 22.17% 19.06% 10.40% 15.00%
difference 12.54% 0.01% -0.91% -3.26%
Utilities 10.50% 12.72% 7.19% 10.18%
.GSPU 5.80% 14.31% 8.59% 15.63%
difference 4.70% -1.59% -1.39% -5.45%
Average Sector 14.35% 18.54% 11.40% 21.64%
Average Benchmark 18.60% 19.50% 11.46% 19.23%
difference -4.25% -0.96% -0.06% 2.40%
True Diversification® 500 17.84% 14.03% 8.47% 16.30%
.SPX 22.15% 15.61% 9.58% 15.57%
difference -4.32% -1.58% -1.12% 0.72%
©2010 Gravity Investments, LLC 19
Duplication or dissemination prohibited without prior written permission.
Table 3: The True Diversification® optimized indices are listed by their sector name and the benchmark GICS sector
is listed by its relevant ticker symbol. We computed the geometrically compounded annualized return for ten the
optimized and benchmark sectors plus the aggregate True Diversification® 500 and its benchmark index for the
sample period of this study, January 2000 – July 2010, using monthly return values. We also computed the
annualized standard deviation, the semi-variance often referred to as downside deviation, and the maximum
drawdown of the respective index. Each optimized index is matched to its benchmark index and the difference
between the relevant risk and return attributes is computed. We also computed the average of each optimized and
benchmark sector as an additional data point for comparison.
Annualized
Return
Standard
Deviation
Semi-
Variance
Maximum
Drawdown
Consumer Staples 5.92% 12.61% 8.85% 31.69%
.GSPS 3.49% 12.02% 8.50% 30.35%
difference 2.43% 0.58% 0.34% 1.34%
Consumer Discretionary 5.02% 21.65% 14.79% 61.49%
.GSPD -0.97% 20.42% 14.40% 56.24%
difference 6.00% 1.23% 0.39% 5.25%
Energy 13.61% 25.49% 16.52% 59.71%
.GSPE 6.45% 20.53% 13.77% 49.76%
difference 7.16% 4.96% 2.75% 9.94%
Financial 3.54% 23.76% 16.55% 73.95%
.GSPF -4.22% 24.62% 18.45% 80.05%
difference 7.76% -0.86% -1.90% -6.10%
Healthcare 7.98% 14.14% 9.94% 35.58%
.GSPA -0.42% 14.39% 10.81% 39.90%
difference 8.40% -0.25% -0.87% -4.32%
Industrial 4.75% 18.58% 13.31% 50.80%
.GSPI 0.54% 19.94% 14.53% 60.24%
difference 4.21% -1.36% -1.22% -9.44%
Information Technology -0.68% 31.30% 21.47% 72.52%
.GSPT -7.14% 29.70% 22.40% 80.35%
difference 6.47% 1.60% -0.93% -7.84%
Material 10.40% 21.10% 13.77% 50.68%
.GSPM 2.92% 22.64% 15.52% 57.87%
difference 7.48% -1.54% -1.75% -7.19%
Telecommunication -6.43% 26.76% 19.19% 78.24%
.GSPL -9.42% 23.29% 17.43% 75.09%
difference 2.99% 3.47% 1.76% 3.15%
Utilities 3.73% 18.60% 12.70% 49.14%
.GSPU -0.27% 18.02% 13.57% 58.58%
difference 4.00% 0.58% -0.87% -9.44%
Average Sector 4.78% 21.40% 14.71% 56.38%
Average Benchmark -0.90% 20.56% 14.94% 58.84%
difference 5.69% 0.84% -0.23% -2.47%
True Diversification® 500 5.82% 16.46% 11.62% 48.64%
.SPX -2.22% 16.26% 12.50% 52.56%
difference 8.04% 0.20% -0.88% -3.91%
©2010 Gravity Investments, LLC 20
Duplication or dissemination prohibited without prior written permission.
Table 4: The monthly returns of the True Diversification® 500 from January 1996 through July 2010.
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
1996 2.82% 0.82% 0.84% 2.66% 0.95% -1.10% -5.91% 2.72% 4.71% 1.11% 5.82% -1.21% 14.63%
1997 3.23% 0.22% -3.97% 2.09% 7.29% 3.06% 7.02% -1.27% 4.59% -3.51% 2.55% 0.33% 23.04%
1998 0.43% 6.43% 4.84% -0.16% -2.70% 2.51% -3.38% -13.01% 9.08% 4.77% 2.71% 6.35% 17.09%
1999 2.67% -4.21% 5.36% 7.69% 1.28% 4.72% -1.16% -1.19% -1.72% 2.18% 0.37% 4.57% 21.80%
2000 -2.82% -1.66% 7.61% -0.81% 1.39% -0.57% -1.61% 6.29% -0.54% 1.55% -4.42% 5.90% 9.95%
2001 0.43% -1.78% -3.35% 6.40% 0.74% -3.15% -0.67% -2.90% -8.07% 0.96% 5.13% 2.42% -4.60%
2002 -2.89% -1.60% 5.98% -3.93% -0.66% -8.06% -10.65% 2.55% -9.80% 9.10% 9.27% -3.68% -15.68%
2003 -2.46% -1.54% 0.40% 6.91% 10.42% 1.17% 0.01% 4.03% -1.13% 4.56% 1.46% 6.77% 34.17%
2004 3.06% 3.49% -0.95% -1.04% 0.28% 3.72% -1.18% -1.14% 4.47% 1.70% 6.97% 1.75% 22.83%
2005 -1.13% 4.28% -1.46% -2.81% 3.63% 3.09% 4.74% 0.65% 2.29% -3.75% 2.80% 1.16% 13.87%
2006 5.62% -1.04% 2.06% 0.79% -1.63% 1.37% 0.60% 1.42% 0.18% 2.91% 2.46% 0.70% 16.36%
2007 1.93% 0.15% 1.57% 3.56% 4.33% -1.78% -3.76% -0.06% 3.49% 1.76% -3.72% 0.98% 8.36%
2008 -7.03% -0.77% -1.67% 5.16% 4.78% -3.76% -5.71% 1.14% -12.33% -20.29% -5.79% 1.56% -38.67%
2009 -3.88% -9.93% 6.18% 11.01% 7.31% -1.43% 5.74% 2.67% 5.71% -4.70% 5.12% 6.94% 32.72%
2010 -2.82% 3.26% 5.76% 1.64% -5.26% -4.67% 6.06% 3.34%
©2010 Gravity Investments, LLC 21
Duplication or dissemination prohibited without prior written permission.
Section 5.2 – Factor Analysis
In this section we use regression analysis in an attempt to identify the characteristics or
factors to which we can attribute our performance as outlined in Section 5.1. For the
purposes of this analysis, we use the full sample of 175 monthly returns for each index
from January 1996 through June 2010. We could not include July 2010 in the analysis as
one of the regression factors was not available for that time period. Table 5 presents the
regression of the optimized and benchmark sectors against a market beta. The market
beta we used is the excess return “RMRF” as applied in Fama-French Q and was
collected from the Ken French website. Table 6 presents the regression results from
evaluating the benchmark sector versus the optimized sector. We also ran a multiple
regression using the benchmark sectors as the market “beta”, and incorporate three
additional factors as explanatory variables; these results are in Table 7. In the multiple
regression analysis we used “SMB” as a proxy for small or large cap, and “HML” as a
proxy for value or growth as defined in Fama-FrenchR. We also incorporated “UMD”
as a proxy for momentum which was originally developed by Jegadeesh and TitmanS
and applied in this context by CarhartT as a fourth factor. The time-series for these
factors were also collected from the Ken French website.
Table 5 shows that attempting to describe or explain the returns of our optimized
indices using the “RMRF” as our market beta is not very productive. The average R2 of
the optimized and benchmark sectors is about 50% which does offers some explanation,
but as a practical matter insufficient. The R2 values indicate that, for the True
Diversification® 500 and .SPX, “RMRF” does offer a reasonable explanation of returns,
but interestingly it does a much better job in explaining the benchmark index rather
than the True Diversification® 500.
We propose that in performing a factor analysis, since we are examining the return
properties of specific sectors, a better market beta (i.e. “RMRF”) would be to use the
respective benchmark GICS sector indices as our market beta. Table 6 supports this
claim with an average R2 across the optimized indices being 82%. However, since we
do not explicitly incorporate “excess returns” by subtracting the risk free rate, the
interpretation of our intercept when we apply the four-factor regression is somewhat
different than would be classically defined in academic literature. We believe our
analysis is very much in the spirit of attempting to identify the potential drivers of our
returns.
We present the results of the four-factor regression in Table 7 and there are some
noteworthy facts. The first is that despite adding three additional variables to the
©2010 Gravity Investments, LLC 22
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regression analysis the average R2 increased by only 3% to 85% indicating, that perhaps,
these “classic factors” do not do a good job at capturing the drivers of returns in our
optimized indices. We feel we can say this for a few reasons. One is that we report
highly statistically significant positive statistics on “SMB” with the exception of our
Telecommunications sector. This suggests that the driver of returns is explained by
small capitalization stocks. Clearly, by using the components of the S&P 500 Index as
the basis of for our universe we do not actually have any small cap stocks in the index.
The second noteworthy observation from Table 7 is that the “HML” betas have a slight
tilt towards “value” as explained by this factor. Although for half of these indices the
“HML” factor is either not statistically significant or the sector can be described as being
“growth”. We think an important take away from this result is that; despite running
the same optimization and portfolio construction process across all of the indices, this
factor cannot consistently explain the returns attributed to our optimized indices.
As with the “HML” beta, the “UMD” beta for momentum as a factor does not
consistently explain the returns attributable to our optimization and portfolio
construction process. We do have a statistically significant loading on the True
Diversification® 500 for momentum. A possible explanation for this result could be the
relatively short history we were forced to use when applying the optimization settings.
Whereas in the sector optimizations we could use up to twenty years of available asset
data, we had only a few years of our optimized sector returns data to work with when
creating the True Diversification® 500, especially in the early years of its construction.
Ex-ante one assumption might be that that however the optimization routine is being
performed there should be a set of corresponding factors that can reliably explain the
return characteristics of the optimized indices. We believe based on this factor analysis
that these traditional factors either cannot explain or do not do an adequate job of
describing the returns associated with our index optimization and portfolio
construction process. The lack of consistent explanation with these factors suggests that
our process of optimization and index construction is unique and different. We think
that in this case, being different is good.
Finally, we note in Table 7 that the beta coefficients of the optimized indices in the
regression, with the exception to our optimized Energy sector, are all below 1 and range
from 0.79 to 0.94. One possible interpretation of this statistic is that by using True
Diversification® optimization in our creating our indices we are reducing the systematic
risk in the indices through a more intelligent allocation of the assets.
©2010 Gravity Investments, LLC 23
Duplication or dissemination prohibited without prior written permission.
Table 5: The results of the regression of the optimized and benchmark indices on the “RMRF” (market excess
returns) beta are presented below. The optimized sectors are listed by name and the benchmark indices are listed by
the appropriate ticker symbols. The test statistics are shown below their respective coefficient and are italicized. The
sample period covered is January 1996 through June 2010.
�� = �� + ������� � + ��
αααα
ββββrmrf R2 αααα
ββββrmrf R2
Consumer Staples 0.003 0.447 35.08% .GSPS 0.002 0.436 28.66%
1.35 9.62 0.78 8.28
Consumer Discretionary 0.001 1.022 69.88% .GSPD -0.001 1.036 77.04%
0.45 20.01 -0.32 24.07
Energy 0.007 0.811 30.83% .GSPE 0.004 0.670 32.43%
1.57 8.72 1.10 9.06
Financial 0.001 0.993 54.61% .GSPF -0.003 1.136 61.68%
0.38 14.39 -0.90 16.66
Healthcare 0.005 0.634 50.76% .GSPA 0.002 0.549 32.74%
2.08 13.32 0.74 9.12
Industrial 0.000 0.884 67.02% .GSPI -0.001 0.999 76.22%
-0.10 18.73 -0.55 23.53
Information Technology 0.001 1.556 73.38% .GSPT 0.000 1.541 72.99%
0.26 21.81 -0.14 21.60
Material 0.002 0.959 56.63% .GSPM -0.002 0.990 56.34%
0.54 15.00 -0.52 14.91
Telecommunication -0.001 1.037 47.34% .GSPL -0.005 0.856 40.90%
-0.22 12.43 -1.23 10.90
Utilities 0.002 0.506 24.82% .GSPU -0.001 0.423 17.75%
0.73 7.49 -0.16 6.03
True Diversification® 500 0.003 0.858 81.90% .SPX -0.002 0.960 97.09%
1.99 27.96 -2.59 75.98
Table 6: The results of the regression of the optimized indices on their respective benchmark index as proxy for
market a beta are presented below. The optimized sectors are listed by name. The test statistics are shown below
their respective coefficient and are italicized. The sample period covered is January 1996 through June 2010.
�� = �� + ��������� � + ��
αααα
ββββsector R2 αααα
ββββsector R2
Consumer Staples 0.002 0.814 77.88% Information Technology 0.002 0.936 86.46%
1.50 24.66 0.82 33.22
Consumer Discretionary 0.002 0.981 89.54% Materials 0.004 0.915 89.61%
1.23 38.46 2.34 38.62
Energy 0.003 1.141 84.46% Telecommunications 0.005 0.982 76.36%
1.33 30.65 1.82 23.62
Financial 0.004 0.864 86.33% Utilities 0.004 0.930 85.49%
2.14 33.03 2.48 31.91
Healthcare 0.004 0.752 66.36% True Diversification® 500 0.004 0.878 81.46%
2.35 18.44 2.96 27.55
Industrials 0.001 0.860 83.05%
0.54 29.09
©2010 Gravity Investments, LLC 24
Duplication or dissemination prohibited without prior written permission.
Table 7: The results of the regression of the optimized indices on their respective benchmark index, as proxy for the
market beta, and two of the three Fama-French factors (SMB and HML) plus the Carhart momentum factor (UMD) is
presented below. The optimized sectors are listed by name. We include the regression results for .SPX using RMRF
as the market beta for comparison purposes. The test statistics are shown below their respective coefficient and are
italicized. The sample period covered is January 1996 through June 2010.
�� = �� + ��������� � + �������� � + � �! � �! � + �"�#�"�# � + ��
αααα
ββββsector ββββSMB ββββHML ββββUMD R2
Consumer Staples 0.002 0.794 0.084 0.104 -0.021 80.56%
1.30 24.70 2.24 2.59 -0.70
Consumer Discretionary 0.001 0.925 0.228 0.253 0.036 92.97%
0.50 38.68 6.24 6.49 1.16
Energy 0.002 1.127 0.195 0.072 -0.021 85.60%
1.05 31.08 3.15 1.08 -0.42
Financial 0.003 0.859 0.115 0.216 0.125 87.42%
1.40 30.68 2.17 3.76 2.86
Healthcare 0.003 0.803 0.357 0.101 0.001 74.49%
1.61 21.38 6.86 1.85 0.02
Industrial 0.000 0.819 0.239 0.217 0.030 87.01%
-0.23 28.94 5.52 4.64 0.82
Information Technology 0.001 0.873 0.525 0.116 -0.046 90.85%
0.34 28.67 8.50 1.46 -0.78
Material 0.003 0.888 0.217 0.094 0.003 91.19%
1.88 38.10 5.14 2.07 0.09
Telecommunication 0.006 0.938 0.128 -0.282 -0.231 79.22%
2.35 22.58 1.65 -3.31 -3.54
Utilities 0.003 0.925 0.156 0.029 -0.038 87.15%
2.27 32.78 3.83 0.65 -1.17
True Diversification® 500 0.003 0.889 0.186 0.201 0.094 84.20%
2.03 27.31 4.44 4.31 2.56
.SPX -0.001 0.993 -0.177 0.052 -0.009 99.32%
-4.09 143.13 -19.57 5.19 -1.11
©2010 Gravity Investments, LLC 25
Duplication or dissemination prohibited without prior written permission.
Section 5.3 – Investment Analysis
Up to this point our analysis and the presentation of our findings had focused on
annualized return numbers and a more “academic” approach. In this section we
present four separate cases that our True Diversification® 500 is a superior investment
relative to its benchmark and represents “better beta”. We feel this is what an investor
could expect – nay, should demand – when undertaking a well diversified long-only
large-cap equity investment. We evaluate and present the monthly returns of our True
Diversification® 500 and the benchmark index by comparing them head-to-head both
monthly and annually. We also evaluate the monthly performance using a rolling
window analysis; this allows us to compare an investment regardless of the starting
point of an investment which can be severely biased depending on the timing of initial
or subsequent investment. We also attempt to remove the timing bias by looking at the
growth of $1000 through time and compare our index to the benchmark with various
starting points. Finally, present an analysis of the returns of what a “401k investor”
might experience when investing on a regular schedule in both indices.
In Table 8 we present the monthly and annual head-to-head numbers for both the True
Diversification® 500 and the benchmark index. A 4.99% annualized outperformance on
its face could be misconstrued that we somehow outperform the index each year by that
amount; that is not the case. On a month-to-month basis the True Diversification® 500
outperforms the benchmark 56% of the time. That may not appear to be particularly
interesting. However, we have a positive asymmetric response to this fact. In months
when we do outperform it is by an average 1.78% and when we underperform it is by
an average of 1.39%. This could be referred to as positive skew, and it is a desirable
investment trait. It is this small incremental compounding effect that we believe is one
of the primary drivers of our outperformance. On a year-to-year basis we beat the
benchmark 73% of the time, and again with a positive asymmetric response.
Remember, the True Diversification® 500 is not intended to track the benchmark index
and this can be seen in Table 8 in the minimum underperformance and the maximum
outperformance. We do not see this as a drawback.
Rolling window analysis is a non-traditional method of analysis, but is frequently used
in the evaluation of alternative investments. Using rolling windows of monthly returns
removes the timing bias of an initial investment and provides a more complete analysis
of an investment’s risk characteristics. We present a six-month, one-year, three-year,
and five-year rolling window analysis in Table 9. To compute the relevant statistics we
used a monthly return series. For each window of analysis we calculate the compound
return experienced during that window and created a time-series of those compounded
©2010 Gravity Investments, LLC 26
Duplication or dissemination prohibited without prior written permission.
returns. This gives us a time-series of each window’s returns that we can use to then
compute the relevant statistics that are presented.
The good way to envision this type of analysis is that it answers the following question:
“Over any consecutive (one-year) window, what are the ranges of possible outcomes for
this investment from a particular statistical perspective?” For example, we found that
the True Diversification® 500 index over every possible consecutive one-year sample
period in the data had a positive return 73.62% of the time which is 6.14% more often
than the benchmark index. A careful examination of Table 9 will show that the
performance of the True Diversification® 500 is consistent and stable. Also, by nearly
every measure available, the True Diversification® 500 was shown to be a superior
method of gaining exposure to a group of large capitalization stocks relative to the
benchmark. An important note on the statistics that are presented in Table 9; they are
presented a raw format and are not converted to an annualized number. For instance,
in the five-year analysis the standard deviation is reported to be 40.37%. This number
could be annualized (approximately) by taking 40.37% and dividing by the square root
of 5 to get an 18% annualized standard deviation.
In Chart 1a we present the growth of a $1000. Chart 1b is the same data as in Chart 1a
but on a log scale to keep the percentage changes equal through time. This method of
analysis can be biased by the choice of starting point. In Table 10 we compute and
compare the total return experienced by an investor in each index starting at the
beginning of each year in our sample through time. Regardless of the timing of an
initial investment, the True Diversification® 500 outperforms the benchmark index
every single time.
In our final analysis of the True Diversification® 500 index as an investment we
examined what a “401k” investor might expect as a return if they made regular
contributions to their investment these indices. In this analysis we assume that at the
beginning of every month the investor adds the same dollar value, in this case $100, to
their investment holdings. Using monthly data we compute the total value of the
investment that would be experienced by each investor. After a total contribution of
$17,500 over the full sample period an investor in the benchmark index would have an
additional $554. Contrast this to an investor in the True Diversification® 500 index; who
after the same $17,500 contribution has accumulated an additional $12,342. This
analysis is presented in Chart 2.
©2010 Gravity Investments, LLC 27
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Table 8: These are the results of comparing monthly and annual calendar returns over the sample period of January
1996 through July 2010.
Monthly Annually
Observations 174 15
Percent Outperformed 56.32% 73.33%
Mean Outperformance 1.78% 8.44%
Mean Underperformance -1.39% -5.84%
Max Outperformance 7.45% 20.09%
Min Underperformance -4.72% -9.61%
Table 9: These are the computed results of a rolling window analysis through time over the full sample period from
January 1996 through July 2010. The six-month, one-year, three-year, and five-year results are presented. An
individual rolling window return is defined as the compound return observed during the defined window. That
return is aggregated into a new time-series and the calculated statistics apply to the time series of calculated window
returns. The difference between the True Diversification® 500 and benchmark index computed and presented to the
right is italicized. The risk ratios are raw and not presented in the traditional annualized format.
Six-Months One-Year
True Diversification® 500 .SPX True Diversification® 500 .SPX
Observations 169 169 163 163
Percent Positive 74.56% 65.68% 8.88% 73.62% 67.49% 6.14%
Mean Return 5.21% 2.84% 2.37% 10.65% 5.79% 4.86% Mean Positive Return 10.62% 10.06% 0.55% 20.11% 17.66% 2.45%
Mean Negative Return -10.63% -10.98% 0.35% -15.75% -18.86% 3.11% Maximum Return 35.35% 38.84% -3.49% 53.82% 50.25% 3.57%
Minimum Return -42.11% -42.70% 0.59% -42.44% -44.76% 2.32%
Standard Deviation 12.40% 13.00% -0.60% 19.33% 20.38% -1.05% Semi-Variance 11.83% 9.85% 1.98% 12.63% 11.06% 1.58%
Sharpe Ratio 0.42 0.22 0.20 0.55 0.28 0.27 Sortino Ratio 0.44 0.29 0.15 0.84 0.52 0.32
Three-Years Five-Years
True Diversification® 500 .SPX True Diversification® 500 .SPX
Observations 139 139 115 115
Percent Positive 74.10% 58.99% 15.11% 98.26% 46.96% 51.30%
Mean Return 34.45% 14.68% 19.77% 60.03% 13.84% 46.19% Mean Positive Return 51.79% 41.08% 10.71% 61.26% 44.40% 16.86%
Mean Negative Return -15.16% -23.31% 8.14% -9.05% -13.21% 4.16%
Maximum Return 115.29% 107.62% 7.67% 174.62% 114.71% 59.91% Minimum Return -35.94% -43.40% 7.46% -12.21% -35.77% 23.56%
Standard Deviation 37.43% 40.62% -3.18% 40.37% 35.71% 4.66% Semi-Variance 8.51% 11.41% -2.90% 4.47% 6.80% -2.33%
Sharpe Ratio 0.92 0.36 0.56 1.49 0.39 1.10
Sortino Ratio 4.05 1.29 2.76 13.43 2.04 11.40
©2010 Gravity Investments, LLC 28
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Chart 1a: The growth of $1000 in the True Diversification® 500 index and the benchmark index from January 1996
through July 2010.
Chart 1b: The growth of $1000 in the True Diversification® 500 index and the benchmark index from January 1996
through July 2010 with the vertical axis in a log base 10 format where each tick on the vertical axis represents $1000.
$0
$500
$1,000
$1,500
$2,000
$2,500
$3,000
$3,500
$4,000
$4,500
$5,000
1996 1998 2000 2002 2004 2006 2008 2010
Growth of $1000 January 1996 - July 2010
True Diversification 500
.SPX
$1,000
1996 1998 2000 2002 2004 2006 2008 2010
Growth of $1000 January 1996 - July 2010
True Diversification 500
.SPX
©2010 Gravity Investments, LLC 29
Duplication or dissemination prohibited without prior written permission.
Table 10: A comparison of the total return of $1000 invested in the respective indices at various starting points
through time. The returns are calculated on a monthly return series with the investment being made on the first day
of each year.
True Diversification® 500 .SPX
1996 254.07% 78.85% 175.22%
1997 208.89% 48.72% 160.18%
1998 151.05% 13.52% 137.53%
1999 114.40% -10.38% 124.78%
2000 76.02% -25.02% 101.05%
2001 60.10% -16.56% 76.66%
2002 67.82% -4.05% 71.87%
2003 99.02% 25.21% 73.82%
2004 48.34% -0.93% 49.27%
2005 20.77% -9.10% 29.87%
2006 6.06% -11.75% 17.81%
2007 -10.58% -23.41% 12.83%
2008 -15.89% -24.98% 9.09%
2009 37.16% 21.96% 15.20%
2010 3.34% -1.21% 4.55%
Chart 2: The accumulation of investing $100 on the first every month in the respective indices from January 1996
through July 2010. The total contribution by the investor is $17,500 over this period and should be subtracted to
compare total investment return.
$0
$5,000
$10,000
$15,000
$20,000
$25,000
$30,000
$35,000
1996 1998 2000 2002 2004 2006 2008 2010
Growth of Regular $100 Monthly Contributions January 1996 - July 2010
True Diversification 500
.SPX
©2010 Gravity Investments, LLC 30
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Section 5.4 – Allocation Analysis
We present in Chart 3 the sector allocations within the True Diversification® 500. There
are a myriad of interesting stories represented by the facts within this chart.
Throughout our process we have applied a diversification centric approach to
constructing our index based on an existing and pre-defined universe. As such, one can
see that through time allocations to various sectors within the True Diversification® 500
shift and are not “traditional” compared to capitalization weighting. We believe we are
adding value to the process by allowing the optimization to allocate to the sectors in
diversification centric manner when we create the True Diversification® 500. This fact is
borne out in Table 1 where we added near 200bps in the sector aggregation process
relative to an equal weighting of the sectors. Also, bear in mind when examining Chart
3 our methodology as outlined in Section 4.1. When aggregating the sectors into the
True Diversification® 500 the optimization process has no future knowledge of a
particular sectors performance. You may be inclined to believe otherwise based on
some of the allocation behaviors presented.
We could have elected to start the True Diversification® 500 index in 1997 since we need
at least one year of historical data from the optimized sectors to implement the
allocation optimization process. Instead, we implemented a “naïve” equal-weight
diversification strategy during the first year of the index to give twelve additional data
points when comparing the True Diversification® 500 to the benchmark index. Our
index construction methodology was quarterly overlapping portfolios; therefore, each
quarter 25% of the sector weight within the index was allocated based on the most
recent optimization. To compute the allocation weights presented in Chart 3 for each
sector through time we calculate the average allocation to each sector over a four
quarter period.
A few interesting observations that can be gleaned from Chart 3; the first is the average
allocation applied to each sector through time. The allocations are reasonably stable,
but do move to over- or under-weight relative to their “typical” allocation. You can
also see that some sectors consistently get higher allocations than others. If you were to
cross-reference these allocation weights to the relative optimized sector performance in
Table 1 you would find that the True Diversification® optimization routine had a strong
tendency to allocate consistently to what ex-post turned out to be the best performing
sectors through time.
Secondly, as we examine the sector allocations as we move toward and through the
“tech bubble” in 2000 there are some interesting things to note. One is that the two
©2010 Gravity Investments, LLC 31
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highest allocations were to Utilities (24%) and Energy (17%) near the peak in Q4 1999.
Many might considered such an aggressive allocation to Utilities to be “defensive” and
to Energy as a “diversifier”. Also, note the allocation to Information Technology which
shrank in the “tech bubble” run-up from 19% in beginning of 1998 to 10% at the end of
1999. Looking at the Consumer Staples sector during the ensuing bear market, the
optimization continued to allocate to a “defensive” sector increasing its allocation
weight to more than 12% during the year 2000. Again, we note that this is “interesting”
behavior that resulted from the True Diversification® optimization process.
Was the True Diversification® optimization able to repeat this “interesting” behavior for
the financial crisis in 2008? In a word, yes. Throughout 2007 and 2008 the sector
allocation to Utilities increased from less than 10% more than 17% taking a “defensive”
posture ahead of the market peak. We also see the same behavior as before in the
allocation to Consumer Staples with a larger and larger allocation as the crisis unfolded.
How about the Financial sector during this period? In Q4 2006 we had an allocation of
11%, by Q4 2007 the True Diversification® 500 had less than a 4% allocation.
Of course True Diversification® optimization didn’t get everything right. The Energy
sector was the highest allocation percentage in the index when crude oil went from $140
to $35/barrel from mid-2008 to early 2009 taking the performance of the sector down
with it. While these stories describing the sector allocations within the True
Diversification® 500 are meant to be anecdotal in nature, they help present the story of
how True Diversification® optimization can consistently add incremental value to an
investment. We also note here that the sector allocation changes through time are not
necessarily predictive, but rather are descriptive of an investment behavior centered on
diversification.
©2010 Gravity Investments, LLC 32
Duplication or dissemination prohibited without prior written permission.
Chart 3: The optimized sector allocations through time within the True Diversification® 500 index. The sector
weights are the average optimized sector weights over a four quarter window to capture the overlapping portfolio
construction process that was implemented. The sample begins with an equal weight allocation in Q1 1996 and is
fully dynamic consistent with the True Diversification® optimization allocations from Q4 1997 through Q3 2010.
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
1996 1998 2000 2002 2004 2006 2008 2010
Sector Allocation Weights True Diversification 500
Utilities
Telecommunications
Material
Information Technology
Industrial
Healthcare
Financial
Energy
Consumer Discretionary
Consumer Staples
©2010 Gravity Investments, LLC 33
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Section 5.5 – Turnover Analysis
Turnover is important consideration when creating an index or investment product as it
has a direct negative impact on performance due to the associated costs of trading.
Some of these trading costs include brokerage commissions, bid/ask spread and market
slippage and are often considered the “hidden cost” of implementing an investment
strategy. Numerous studies have examined these costs that are borne by an investor in
mutual funds. Mark CarhartU and John BogleV are two studies that were done in the
1990’s that calculated the negative impact of turnover and found that the cost for every
100% in turnover to be 0.95% and 1.2% respectively. A more recent study by David
Blanchett from 2001 to 2006 found substantially lower costs associated with turnover
which is consistent with a long-term industry trend of lower commissions, improved
liquidity, and efficient execution algorithms. Blanchett found that the trading costs per
100% of turnover for large capitalization equities to be 0.19% and across all
capitalizations, including international equities, to be 0.48%W.
We computed the portfolio turnover of the True Diversification® 500 in an attempt to
quantify the implementation costs associated with this index based on our index’s
turnover. For the purposes of this analysis we define turnover as the absolute change in
percentage allocation of an asset from one period to the next. Given our choice of index
construction, which includes two layers of True Diversification® optimization and
quarterly overlapping portfolios, we computed turnover using two different methods in
an effort to establish a range of estimates.
The first method computed the absolute percent change in allocation for an asset from
one quarter to the next for each sector. If an asset’s optimized allocation moved from
1% to 2% between quarters we record this as a 1% change. If the asset is no longer
listed in the subsequent quarter then the percent change is just the asset’s prior
allocation. In the case where a new asset is added in the subsequent quarter then the
percent change is the new allocation percent. Summing the total of these absolute
changes for a sector gives us a turnover figure from one quarter to the next for a sector.
We compute this turnover each quarter and for each sector. We then compute the
portion of turnover associated with each sector based on the sector weights within the
True Diversification® 500 by multiplying the sector turnover by the sector weight.
Because we are using quarterly overlapping portfolios, we compute a four quarter
average of each sector’s turnover within the True Diversification® 500. Summing these
turnover figures gives us the average turnover in the True Diversification® 500 over the
preceding four quarters and from this we can create a time-series of these average
turnover figures. We found that the turnover computed in this manner averaged 62%
per year with a range of 58% to 66%.
©2010 Gravity Investments, LLC 34
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The second method we used to quantify portfolio turnover is very similar to the first
however in the case where an asset is present in each quarter we take one-fourth of the
absolute percentage change in allocations to mimic the effects of applying quarterly
overlapping based index construction method. However, in the case of additions or
deletions we still take the full percentage change during that quarter. In both methods
of computing our turnover this severely biases the turnover rate higher relative to how
we computed the returns for the index. The returns assume that additions and
deletions are added incrementally through time, whereas these methods of turnover
computation overstate the turnover at each quarter. As before, we compute and sum
the absolute change in percent allocations from one quarter to the next for each sector
and multiply those turnover figures by the respective weight of each sector in the True
Diversification® 500. Adding these quarterly sector turnover figures gives us a total
turnover figure for that quarter. As before, we compute a time-series of rolling one year
periods, this time by summing rather than averaging over four quarters. We found that
turnover computed using this methodology to be on average 68% per year and the
range of turnover was 74% to 63%.
We intentionally attempted to conservatively state our turnover figures by penalizing
additions and deletions as they occurred rather than smooth their turnover over a one-
year period which would be more consistent with our index construction. The turnover
rate at 60-70% per year is remarkably consistent through time which is not always the
case with capitalization-weighted indices. This turnover figure is comparable to the
median turnover of a mutual fundX. Our turnover is higher than the typical turnover
reported in capitalization index funds. From 2002 – 2008 the SPY ETF reported
turnover of 4% but the range in turnover was 1% to 9% per year. Other alternative
equity indices report higher turnover. For example over the same period the equal
weight S&P 500 ETF, EW, had turnover of 22% per yearY. We believe that the superior
investment results of the True Diversification® 500 more than make up for the potential
costs associated with this level of turnover.
Section 6 – Conclusion
The application of Diversification Optimization to a defined universe, herein the S&P
500, was able to consistently generate greater returns with commensurate, but slightly
lower risk measurements. The results of this research support the efficacy of
diversification as an index construction methodology for an enduring, systematic
investment product, or series of products based on True Diversification®. The relative
superiority of True Diversification during the “lost decade” is of particular consequence
for investors seeking exposure to equities during periods of lower estimated returns.
©2010 Gravity Investments, LLC 35
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The ex-post 499 basis points of incremental performance over the index, we believe
constitute the best estimation of forward, relative performance of this methodology.
The consistency and flexibility of the model lend it to numerous applications and
investment products.
The raw database results of this research are available to select enterprise clients and
partners under applicable agreements.
©2010 Gravity Investments, LLC 36
Duplication or dissemination prohibited without prior written permission.
Appendix
This table shows the variation in risk and return values based on the method of portfolio construction, optimization
frequency, and holding period length. All ten sectors and the True Diversification 500 are included using the full
sample data from January 1996 through July 2010. We highlight the construction process in yellow for ease of
comparison. The annualized returns presented were computed from daily returns by taking the average return and
multiplying by 252. Likewise the standard deviation was compute from daily returns and multiplied by the square
root of 252 to annualize it. This method is not as accurate as computing the geometrically compounded return and
therefore is not directly comparable to the returns presented in the body of the paper, but these calculations are
useful as a quick comparison and demonstrates regardless of method of index construction True Diversification®
optimization generated superior performance and we did not selectively choose the “best” construction method.
Overlapping Portfolio No No No No Yes Yes Yes No No No
Optimization Quarter 1 2 3 4 1 , 3 2 , 4 1 , 2 , 3 , 4 1 , 3 2 , 4 1 , 2 , 3 , 4
Holding Period Annual Annual Annual Annual Annual Annual Annual Semi Semi Quarterly
Return
Consumer Staples 7.86% 7.53% 7.76% 6.89% 7.83% 7.21% 7.52% 7.01% 7.13% 7.35%
Consumer Discretionary 9.64% 10.37% 9.25% 8.30% 9.48% 9.33% 9.41% 9.51% 10.00% 9.70%
Energy 17.20% 14.60% 15.96% 17.10% 16.59% 15.85% 16.22% 16.64% 15.81% 16.45%
Financial 10.77% 11.82% 12.33% 8.49% 11.57% 10.16% 10.86% 12.06% 9.19% 9.06%
Healthcare 10.97% 10.65% 11.02% 11.07% 11.02% 10.93% 10.91% 11.31% 10.89% 12.25%
Industrial 5.94% 8.41% 5.47% 7.49% 5.73% 7.95% 6.84% 6.54% 7.66% 7.54%
Information Technology 10.61% 12.99% 11.98% 13.86% 11.33% 13.43% 12.38% 11.57% 14.22% 12.25%
Material 9.54% 10.76% 9.30% 9.23% 9.48% 10.00% 9.74% 9.60% 10.22% 10.56%
Telecommunications 6.50% 7.41% 7.71% 7.08% 7.12% 7.24% 7.18% 5.79% 6.21% 5.31%
Utilities 7.63% 6.37% 6.84% 8.78% 7.25% 7.57% 7.41% 8.63% 6.77% 7.72%
True Diversification® 500 9.66% 10.54% 11.65% 10.33% 10.66% 10.43% 10.59% 10.94% 10.28% 10.21%
Standard Deviation
Consumer Staples 15.36% 15.26% 15.25% 15.34% 15.19% 15.19% 15.12% 15.57% 15.34% 15.57%
Consumer Discretionary 22.82% 22.67% 22.61% 22.29% 22.61% 22.38% 22.46% 22.86% 22.74% 22.95%
Energy 31.26% 30.40% 30.96% 31.14% 31.00% 30.65% 30.79% 31.42% 31.31% 31.69%
Financial 29.74% 30.00% 30.79% 29.53% 29.83% 29.48% 29.53% 32.48% 30.22% 31.37%
Healthcare 19.46% 19.05% 19.53% 19.08% 19.30% 18.88% 19.02% 19.65% 19.19% 19.57%
Industrial 20.25% 19.90% 20.25% 20.83% 20.15% 20.22% 20.14% 20.47% 20.64% 20.88%
Information Technology 30.16% 29.85% 30.45% 31.00% 30.13% 30.22% 30.10% 30.69% 30.83% 31.10%
Material 22.83% 23.61% 22.72% 23.51% 22.64% 23.39% 22.93% 22.89% 23.98% 23.94%
Telecommunications 27.66% 27.48% 26.59% 27.71% 26.82% 27.28% 26.95% 28.21% 28.12% 28.79%
Utilities 20.63% 20.14% 19.42% 20.36% 19.84% 20.05% 19.88% 20.41% 20.83% 21.03%
True Diversification® 500 20.27% 19.59% 19.72% 20.22% 19.93% 19.86% 19.51% 19.87% 19.85% 19.91%
Sharpe Ratio
Consumer Staples 0.51 0.49 0.51 0.45 0.52 0.47 0.50 0.45 0.46 0.47
Consumer Discretionary 0.42 0.46 0.41 0.37 0.42 0.42 0.42 0.42 0.44 0.42
Energy 0.55 0.48 0.52 0.55 0.54 0.52 0.53 0.53 0.51 0.52
Financial 0.36 0.39 0.40 0.29 0.39 0.34 0.37 0.37 0.30 0.29
Healthcare 0.56 0.56 0.56 0.58 0.57 0.58 0.57 0.58 0.57 0.63
Industrial 0.29 0.42 0.27 0.36 0.28 0.39 0.34 0.32 0.37 0.36
Information Technology 0.35 0.44 0.39 0.45 0.38 0.44 0.41 0.38 0.46 0.39
Material 0.42 0.46 0.41 0.39 0.42 0.43 0.42 0.42 0.43 0.44
Telecommunications 0.23 0.27 0.29 0.26 0.27 0.27 0.27 0.21 0.22 0.18
Utilities 0.37 0.32 0.35 0.43 0.37 0.38 0.37 0.42 0.32 0.37
True Diversification® 500 0.48 0.54 0.59 0.51 0.53 0.53 0.54 0.55 0.52 0.51
©2010 Gravity Investments, LLC 37
Duplication or dissemination prohibited without prior written permission.
A True Diversification® is a registered trademark of Gravity Investments, LLC. James
Damschroder, the founder of Gravity Investments, LLC, holds several patents awarded
and pending related to diversification. Creating a Visual Representation of a Portfolio,
U.S. patent number 7,472,084; Diversification Measurement and Analysis System, U.S.
patent application 20,090,292,648;
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