Archive for January 2014
1. Equity premium is the additional “wage” one can earn from taking stock market risk over not taking stock market risk.
2. Small cap premium is the additional “wage” one can earn from taking small company risk over taking large company risk.
3. Value premium is the additional “wage” one can earn from taking non-growing company risk over taking growing company risk.
Those who are ardent believers of an efficient market such as Nobel Prize winner Eugene Fama usually believe all returns should be the result of taking risk and that simple actions like rebalancing periodically should not produce additional returns.
Those who believe the market is emotion-driven, such as Nobel Prize winner Robert Shiller, believe in a rebalancing “bonus”. Since the market is either over-priced or under-priced from time to time, rebalancing allows us to take advantage of this market mispricing.
The return differential of RSP vs SPY provides an excellent control experiment to test whether this illustrious rebalancing “bonus” actually exists. SPY and RSP invest in the same 500 largest stocks of the US. SPY being a cap-weighted fund, does not require rebalancing, while RSP being a equally weighted fund requires periodic rebalancing.
Since its inception on March 9, 2003, RSP has returned 193%. At the same time, SPY has only returned 97%. This is extremely puzzling as both RSP and SPY hold the same S&P 500 stocks.The only difference is that SPY is a cap-weighted fund and RSP is an equally-weighted one. This begs the question, is RSP’s outperformance normal; and more importantly, is it likely to continue?
To answer the question I asked my intern Nahae Kim to run a regression based on the Nobel Prize winning Fama-French Three Factor Model.
R(x) – rf = alpha + beta1*(Rmkt – rf) + beta2*SML + beta3*HML
Where R(x) is the return of the selected fund, x being either RSP or SPY, alpha is the “skill” of the fund, beta1 is the market risk loading, beta2 is the small cap risk loading and beta3 is the value risk loading.
Here is what I got from the two regressions.