Why Active Investing is a Negative Sum Game

In this article well known academics Eugene Fama and Kenneth French reflect on Nobel Laureate William F Sharpe's 1991 article on the arithmetic of active fund management. This has already been discussed on this blog and you can see a copy of that article here

Cutting through the slightly complex jargon that is used by Fama and French,the essence of what they are saying is that the combined portfolios all active investors have the same weighting in shares as the market as a whole. This means that the combined portfolios can only perform the same as the market, less their costs. It also means that the only way in which an active investor can outperform the market is to do so at the expense of other active investors.

In contrast, passive investors also all hold the same weighting in shares as the market as a whole. This means that their portfolios should perform the same as the market, less their costs. However, as their costs are less than those of active investors, passive investors as a group must outperform active investors.

This article does not seek to deny that some active investors do outperform the market. It is just that their gains have been made at the expense of other equally clever active investors. Other research has shown that winners tend not to repeat and that on the whole, they do not tend to remain winners for very long.

When considering whether to invest actively or passively you have to answer the question 'Are you feeling lucky?' For active investors the answer must be 'Yes' - in the face of the evidence. For passive investors the answer is 'No - but at least I will be assured of returns that essentially replicate the market less my costs which are substantially less than for active portfolios'.

From a financial planning point of view, investing should not be seen as a game. Investments are not an end in themselves. Instead they are the means by which individuals fund for the serious financial goals, which they need to achieve in order to lead the future lifestyles that they desire. Speculation on which fund manager is likely to provide better returns than another, in the face of evidence that this is likely to be an unsuccessful strategy, has no place in this process.

Chris Wicks CFP
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