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Black Swans, Rogue Waves, and Wall Street
Or, Why the Sudden Demise of Wall Street Really Shouldn't Be Shocking
"The End of Wall Street" was the title of an editorial today in the country's best-known financial newspaper. It went on to say, "Wall Street as we've known it for decades has ceased to exist." It's true.
Several commentators have noted how the speed of Wall Street's demise has been as shocking as the event itself. I understand that sense of shock, but I do not share it. Instead, I find this rapidly sudden change to be fitting.
Please let me say clearly that I do not mean "fitting" in the sense that Wall Street somehow "had it coming." No one should take pleasure in the downfall of American institutions like Goldman Sachs, Morgan Stanley, Merrill Lynch, Lehman Brothers and Bear Stearns. Anyone who is tempted by that thought needs to know that most of the job losses in lower Manhattan will not involve millionaire traders, but the clerical workers, janitors and bookkeepers who ride the subway to work from the outer boroughs.
Here's what I do mean by fitting: Most risk management strategies on Wall Street were based on the "efficient market hypothesis." For decades, this school of thought advocated notions such as buy & hold, the random walk, and portfolio diversification. It claimed that investors are rational, denied that price movements are patterned, and insisted that successful market timing was impossible.
Yet in recent years, economists of the behavioral finance school have produced research that debunks the efficient market hypothesis. Other scholars have shown that financial markets and even history itself are dominated by "Black Swans" -- major trend reversals and events that happen suddenly and without warning.
Wall Street was dominated by linear models that assumed rational investors and efficient markets. Non-linear events didn't fit those models. But now Wall Street has been hit by the equivalent of a "Rogue Wave," the 100-foot wall of water that suddenly swells up in a perfectly calm ocean -- mariners spoke of them for centuries, while oceanographers dismissed them as fable. Satellite photography has conclusively proven the mariners right.
Statistical models are linear by nature, based on averages and probabilities. Some can account for the outliers, but will assign them a probability of appearing only once in a thousand years. Your reliance on these assumptions can be measured by the shock you feel over the demise of Wall Street in the space of one week.
Our method of analysis is NON-linear. We expect turns and trends in price, even as we allow the pattern -- not computers -- to reveal the probabilities. Come discover the difference for yourself, with a Financial Forecast Subscription. Click here to learn more.
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