Academic / efficient marketsb. 1932American

Burton Malkiel

A Random Walk Down Wall Street

The economist who suggested a blindfolded monkey throwing darts could match the professionals — and then spent fifty years being mostly right about it.

Malkiel is a Princeton economist whose 1973 book A Random Walk Down Wall Street did more to popularise index investing than any fund marketing ever managed. It has been revised more than a dozen times and is still the standard argument against paying for stock selection.

The line everyone remembers is that a blindfolded monkey throwing darts at the stock listings could select a portfolio that does as well as one chosen by experts. The Wall Street Journal turned it into a running contest against professional analysts. The darts did well enough that the joke stopped being purely a joke.

His actual claim is narrower and harder to dismiss than the caricature. Malkiel does not argue prices are always correct; he argues that inefficiencies are small, competed away quickly, and difficult enough to exploit that the average attempt loses to its own costs. Decades of persistent underperformance by active funds have been kind to that position.

The useful thing he leaves behind is methodological. Random selection is the baseline any claimed skill must clear, and a strategy that has not been measured against a randomly-chosen portfolio under the same constraints has not really been measured at all.

The ideas that survived

The random walk: Past price movements carry little information about future ones. Most chart patterns are the human tendency to find structure in noise, formalised and sold.
The dart-throwing monkey: Malkiel's famous provocation. The Wall Street Journal ran it for years against real analysts; the darts were competitive, which was the point.
Efficiency is a claim about difficulty, not perfection: Malkiel's position is not that prices are always right — it is that mispricings are hard enough to find and exploit that most attempts lose to costs.
A random baseline is the honest comparison: Any strategy claiming skill has to beat what random selection would have produced. Most published records are never tested against that bar.

Books

A Random Walk Down Wall Street1973

Elsewhere

Wikipedia

Biographical reference only. Nothing here is investment advice, and no affiliation with or endorsement by the people profiled is implied.

The ideas that survived

The random walk

Past price movements carry little information about future ones. Most chart patterns are the human tendency to find structure in noise, formalised and sold.

The dart-throwing monkey

Malkiel's famous provocation. The Wall Street Journal ran it for years against real analysts; the darts were competitive, which was the point.

Efficiency is a claim about difficulty, not perfection

Malkiel's position is not that prices are always right — it is that mispricings are hard enough to find and exploit that most attempts lose to costs.

A random baseline is the honest comparison

Any strategy claiming skill has to beat what random selection would have produced. Most published records are never tested against that bar.