september 15, 2008: a market analysis
TRANSCRIPT
September 15, 2008: A Market Analysis By Anthony Renshaw, PhD Director, Applied Research September 17, 2008 © Copyright, Axioma, Inc. 2008 - All rights reserved Introduction
September 15, 2008 was a difficult day for Wall Street, as major announcements concerning AIG,
Lehman Brothers, and Merrill Lynch triggered the worst market sell-off since the first day of
trading after the September 11, 2001 terrorist attacks.
This short article analyzes the market situation using Axioma US fundamental risk model. In
addition to identifying the factors that drove Monday’s returns, the results highlight recent
changes in market conditions that may be important to portfolio managers.
Key findings include:
• The standard factor return for Leverage on 9/15 was -9.93, a value of extraordinary
magnitude. All but one industry suffered negative standard factor returns on this day,
several with values less than -5.0.
• The two style factors with the most negative recent cumulative factor returns –
Leverage and Medium-term Momentum – have also experienced significant changes in
their recent correlations with the other style factors. The style factor with the largest
recent cumulative factor return – Liquidity – has experienced relatively stable
correlations with other style factors.
• Although the overall level of market turnover on 9/16/08 is similar to that of 8/8/2007,
so far market turnover does not exhibit the same level of factor dependence as it did in
August 2007 when quantitative managers experienced far more difficulties than other
portfolio managers.
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Daily Factor Return Analysis
Figure 1 shows the cumulative factor returns for Axioma’s nine, US style risk factors from July
31, 2008 through the close of September 16, 2008. The two, most negative returns are for
Leverage and Medium-term Momentum. The only factor with a significant positive return over
this time period is Liquidity. Several other factors have also experienced negative factor returns,
namely Volatility, Short-term Momentum, and Size.
Figure 1. Cumulative factor returns for Axioma’s nine, US style risk factors.
The magnitude of the sell-off on September 15 is most easily illustrated using standardized factor
returns1. Figure 2 shows the standard factor returns for Axioma’s nine, US style risk factors.
Figure 2. Standard daily factor returns for Axioma’s nine, US style risk factors.
The standard factor return for Leverage on 9/15 was -9.93, a factor return that dwarfs all the other
returns on the chart. Several other factors also had significant standard factor returns: Short- 1 Standard factor returns are daily factors returns normalized by subtracting off the mean and dividing by the standard deviation. We used the previous 750 trading days to define the mean and standard deviation for each factor.
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term Momentum (+3.01), and Volatility (-4.27). On 9/16, the largest factor return was Liquidity
(+4.43).
Table 1 below lists the standard factor returns for the Industry factors for 9/15. The only industry
with a positive return was Airlines (+0.41). All others were negative, significantly so, starting
with Wireless Telecommunication Services (-5.40).
Industry
Std. Daily
Factor
Return Industry
Std. Daily
Factor Return
Wireless Telecommunication Services -5.40 Health Care Equipment & Supplies -3.58
Construction & Engineering -5.33 Multi-Utilities -3.55
Independent Power Producers & Energy Traders -5.21 Chemicals -3.53
Diversified Telecommunication Services -5.19 Electric Utilities -3.50
Oil, Gas & Consumable Fuels -5.08 Food Products -3.45
Gas Utilities -4.94 Health Care Providers & Services -3.33
Diversified Financial Services -4.68 Water Utilities -3.28
Computers & Peripherals -4.47 Automobiles -3.27
Beverages -4.41 Marine -3.14
IT Services -4.29 Machinery -3.06
Real Estate Investment Trusts (REITs) -4.15 Household Durables -2.92
Insurance -4.14 Auto Components -2.89
Consumer Finance -4.14 Paper & Forest Products -2.86
Media -4.07 Biotechnology -2.74
Trading Companies & Distributors -3.96 Office Electronics -2.71
Real Estate Management & Development -3.95 Transportation Infrastructure -2.60
Life Sciences Tools & Services -3.94 Tobacco -2.26
Metals & Mining -3.92 Internet Software & Services -2.18
Energy Equipment & Services -3.88 Thrifts & Mortgage Finance -2.12
Pharmaceuticals -3.85 Semiconductors & Semiconductor Equipment -1.98
Electrical Equipment -3.85 Textiles, Apparel & Luxury Goods -1.90
Household Products -3.79 Multiline Retail -1.79
Commercial Services & Supplies -3.74 Road & Rail -1.62
Building Products -3.72 Specialty Retail -1.54
Communications Equipment -3.71 Construction Materials -1.50
Industrial Conglomerates -3.66 Air Freight & Logistics -1.41
Capital Markets -3.64 Diversified Consumer Services -1.26
Health Care Technology -3.62 Distributors -1.14
Food & Staples Retailing -3.62 Hotels Restaurants & Leisure -1.13
Commercial Banks -3.61 Personal Products -0.92
Containers & Packaging -3.61 Leisure Equipment & Products -0.82
Software -3.60 Internet & Catalog Retail -0.33
Electronic Equipment & Instruments -3.59 Airlines 0.41
Aerospace & Defense -3.58 Table 1. Standard daily factor returns on 9/15/08 for the 67 GICS industries.
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Changes in Factor-Factor Correlations
Table 2 illustrates how the correlations between the nine style factors have changed recently.
The factor-factor correlations predicted by Axioma US risk model were averaged over two time
windows: 9/17/07 to 7/31/08 and 7/31/08 to 9/16/08. These are shown in the table, together with
a column giving the difference in correlations, with the factor-factor pairs sorted by the
differences.
Factor 1 Factor 2
Average Risk
Model Correlation
9/17/07 to 7/31/08
Average Risk
Model Correlation
7/31/08 to 9/16/08
Correlation
Difference
Medium-Term Momentum Market Sensitivity 0.028 -0.251 -0.279
Medium-Term Momentum Size 0.297 0.062 -0.235
Medium-Term Momentum Growth 0.298 0.071 -0.227
Medium-Term Momentum Value -0.008 -0.231 -0.223
Short-Term Momentum Market Sensitivity -0.053 -0.204 -0.152
Growth Value 0.200 0.112 -0.088
Liquidity Leverage 0.094 0.009 -0.085
Size Growth 0.245 0.166 -0.079
Short-Term Momentum Growth -0.111 -0.188 -0.077
Volatility Short-Term Momentum -0.111 -0.168 -0.057
Medium-Term Momentum Leverage -0.189 -0.244 -0.055
Short-Term Momentum Leverage -0.004 -0.053 -0.049
Short-Term Momentum Liquidity -0.185 -0.221 -0.036
Volatility Market Sensitivity 0.635 0.605 -0.030
Volatility Medium-Term Momentum -0.013 -0.037 -0.023
Short-Term Momentum Value -0.276 -0.284 -0.008
Short-Term Momentum Size 0.108 0.103 -0.004
Liquidity Value 0.017 0.018 0.001
Market Sensitivity Size 0.185 0.187 0.002
Volatility Liquidity 0.239 0.244 0.005
Volatility Size 0.322 0.329 0.007
Medium-Term Momentum Liquidity -0.364 -0.357 0.008
Volatility Growth 0.157 0.169 0.012
Volatility Value 0.019 0.037 0.017
Liquidity Growth -0.041 -0.022 0.019
Market Sensitivity Growth 0.130 0.169 0.039
Liquidity Size -0.291 -0.249 0.042
Growth Leverage -0.102 -0.035 0.067
Volatility Leverage 0.262 0.342 0.080
Liquidity Market Sensitivity 0.136 0.233 0.097
Size Value 0.039 0.152 0.113
Market Sensitivity Leverage 0.239 0.367 0.128
Leverage Value -0.164 -0.005 0.158
Medium-Term Momentum Short-Term Momentum 0.089 0.282 0.193
Market Sensitivity Value -0.099 0.123 0.222
Size Leverage 0.042 0.284 0.242
Table 2. Recent changes in Style factor-factor correlations. Factor pairs with either Medium-term Momentum or Leverage have been highlighted.
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Several of these changes may be of significance to portfolio managers. The four correlations with
the most, negative changes all involve Medium-term Momentum, as does the third most positive
correlation. This indicates that the behavior of Medium-term Momentum over the last month and
a half has been significantly different than in the preceding year. This is supported by the
cumulative factor returns shown in Fig. 1. Note that the correlations differences in these cases are
as great as or greater than the current correlation.
Not surprisingly, the other factor with significant changes has been Leverage, which is in three of
the top five correlation changes.
Market Turnover
Recent research by Axioma has shown that market events are often associated with factor-
dependent changes in market turnover where market turnover is defined as an asset’s daily
volume divided by its market capitalization.2 In particular, the events of last August 2007 when
many quantitative portfolio managers significantly underperformed the market were shown to be
strongly linked to an increase in market turnover as a function of an asset’s exposure to style risk
factors.
For the events of 9/15 and 9/16, there does not appear to be any strong factor related increase in
market turnover although market turnover did increase overall on 9/16 for several factors to
levels commensurate with those of last August. This raises the possibility of a future, factor-
dependent liquidity event. Figs. 3 - 7 show market turnover as a function of exposure to
Leverage, Medium-term Momentum, Value, Market Sensitivity, and Volatility. Figure 8 shows
market turnover as a function of the ten GICS sectors. Overall, there are no systematic trends like
those experienced last August apart from the increased market turnover on 9/16.
2 “Recent Market Turnover and Risk Factor Exposure,” by A. A. Renshaw, in Axioma Advisor, August 2008. Available at www.axiomainc.com.
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Figure 3. Market turnover (%) as a function of Leverage exposure.
Figure 4. Market turnover (%) as a function of Medium-term Momentum exposure.
Figure 5. Market turnover (%) as a function of Value exposure.
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Figure 6. Market turnover (%) as a function of Market Sensitivity exposure.
Figure 7. Market turnover (%) as a function of Volatility exposure.
Figure 8. Market turnover (%) as a function of the ten GICS sectors.