An ongoing debate in finance is whether “active” investment strategies can outperform “passive” strategies. The empirical evidence in favor of passive strategies which appears in studies published by peer-reviewed scientific journals is overwhelming. For example, in studies of mutual fund performance, passive strategies almost always blow away active strategies. Similarly, the empirical evidence on frequency of trading by “retail” customers is that on average, portfolio performance is inversely related to trading frequency; i.e., the more people trade, the worse they do. Even hedge funds chronically underperform passive investment strategies. For example, the authors of a 2011 Journal of Financial Economics (JFE) article entitled “Higher risk, lower returns: What hedge fund investors really earn” find that hedge fund returns are on the magnitude of 3% to 7% lower than corresponding buy-and-hold fund returns, reliably lower than the return on the Standard & Poor’s (S&P) 500 index, and only marginally higher than the riskless rate of interest.
In my opinion, if you were to read only one book about finance, it would have to be “A Random Walk Down Wall Street: The Time-Tested Strategy for Successful Investing” by Burton G. Malkiel. Malkiel’s book (now in its 11th edition) provides a compelling argument in favor of efficient markets theory and investing in (passively managed) index funds.
Efficient market theory implies that stock prices follow a random walk. These ideas were originally conceived of by Professors Paul Samuelson and Eugene Fama in the 1960’s, and subsequently popularized by folks like Professor Malkiel. In Finance 4366, we rely extensively upon the notion that prices of speculative assets (e.g., stocks, bonds, commodities, foreign exchange, etc.) follow random walks as we consider the technical details associated with pricing and hedging risk using financial derivatives.