Thursday, September 20, 2007
So how much did quantitative strategies actually lose last quarter?
The numbers have started to come in: Morgan Stanley lost $480MM last quarter due to quantitative trading -- about 10% of operating profits.
Wednesday, September 19, 2007
Hedge fund replication
I wrote about how hedge fund returns can be replicated with simple factor models. I just learn that IndexIQ, a company in Rye Brook, NY,
Monday, September 17, 2007
More discussion on returns, risk and leverage
Previously I discussed an important debate on whether it is better to increase a portfolio's return by taking on more risks (e.g. holding high-beta stocks), or by increasing leverage but holding low-risk assets. A reader Mr. F. Sudirga has kindly send me some other research papers supporting the conclusion that increasing leverage is the preferred way.
In a paper titled "Risk Parity Portfolios", Dr. Edward Qian at PanAgora Asset Management argued that a typical 60-40 asset allocation between stocks and bonds is not optimal because it is overweighted with risky assets (stocks in this case). Instead, to achieve a higher Sharpe ratio while maintaining the same risk level as the 60-40 portfolio, Dr. Qian recommended a 23-77 allocation while leveraging the entire portfolio by 1.8. The stock-bond dichotomy is for illustration only -- the results can be improved further by including other asset classes such as commodities.
The only reservation I have with all this enthusiasm with increasing leverage is one that many risk-managers are aware of: most of the research uses concepts such as standard deviations to measure risk. But as the LTCM debacle as well as the recent subprime mortgage meltdown has reminded us, risky events have fat-tailed distributions. Therefore, one should be very wary of using standard deviation as the sole determinant of leverage.
In a paper titled "Risk Parity Portfolios", Dr. Edward Qian at PanAgora Asset Management argued that a typical 60-40 asset allocation between stocks and bonds is not optimal because it is overweighted with risky assets (stocks in this case). Instead, to achieve a higher Sharpe ratio while maintaining the same risk level as the 60-40 portfolio, Dr. Qian recommended a 23-77 allocation while leveraging the entire portfolio by 1.8. The stock-bond dichotomy is for illustration only -- the results can be improved further by including other asset classes such as commodities.
The only reservation I have with all this enthusiasm with increasing leverage is one that many risk-managers are aware of: most of the research uses concepts such as standard deviations to measure risk. But as the LTCM debacle as well as the recent subprime mortgage meltdown has reminded us, risky events have fat-tailed distributions. Therefore, one should be very wary of using standard deviation as the sole determinant of leverage.