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Mental Models

Rare Events

Taleb argues that rare events can be underpriced when traders focus on how often a bet wins rather than the size of its gains and losses. His asymmetric bets seek infrequent payoffs large enough to outweigh repeated losses.

THE IDEA

Rare Events

The best description of my lifelong business in the market is “skewed bets,” that is, I try to benefit from rare events, events that do not tend to repeat themselves frequently, but, accordingly, present a large payoff when they occur. I try to make money infrequently, as infrequently as possible, simply because I believe that rare events are not fairly valued, and that the rarer the event, the more undervalued it will be in price. In addition to my own empiricism, I think that the counterintuitive aspect of the trade (and the fact that our emotional wiring does not accommodate it) gives me some form of advantage.

Why are these events poorly valued? Because of a psychological bias; people who surrounded me in my career were too focused on memorizing section 2 of The Wall Street Journal during their train ride to reflect properly on the attributes of random events. Or perhaps they watched too many gurus on television. Or perhaps they spent too much time upgrading their PalmPilot. Even some experienced trading veterans do not seem to get the point that frequencies do not matter. Jim Rogers, a “legendary” investor, made the following statement:

I don’t buy options. Buying options is another way to go to the poorhouse. Someone did a study for the SEC and discovered that 90 percent of all options expire as losses. Well, I figured out that if 90 percent of all long option positions lost money, that meant that 90 percent of all short option positions make money. If I want to use options to be bearish, I sell calls.

Visibly, the statistic that 90% of all option positions lost money is meaningless, (i.e., the frequency) if we do not take into account how much money is made on average during the remaining 10%. If we make 50 times our bet on average when the option is in the money, then I can safely make the statement that buying options is another way to go to the palazzo rather than the poorhouse. Mr. Jim Rogers seems to have gone very far in life for someone who does not distinguish between probability and expectation (strangely, he was the partner of George Soros, a complex man who thrived on rare events).

One such rare event is the stock market crash of 1987, which made me as a trader and allowed me the luxury of becoming involved in all manner of scholarship. Nero of the smaller house in Chapter 1 aims to get out of harm’s way by avoiding exposure to rare events—a mostly defensive approach. I am far more aggressive than Nero and go one step further; I have organized my career and business in such a way as to be able to benefit from them. In other words, I aim at profiting from the rare event, with my asymmetric bets.

When to use it

  • An investor buys out-of-the-money put options during a bull market as a hedge against a market crash.

  • An entrepreneur launches a startup with a small probability of becoming a massive success but high payoff.

  • A researcher pursues a high-risk, high-reward scientific hypothesis that could revolutionize the field.

FROM THEORY TO EVERYDAY LIFE

In practice

01

The Option Statistics Fallacy

Jim Rogers argued that buying options leads to losses because 90% expire worthless. However, this ignores the magnitude of gains when options are in the money. A 90% loss rate can still yield huge profits if the average win is large.

02

The 1987 Stock Market Crash

Taleb reports that profiting during the 1987 crash established his trading career and gave him the financial freedom to pursue scholarship.

✳

A MOMENT TO REFLECT

Put it to work.

  1. How might the focus on frequency rather than expectation lead to poor investment decisions?

  2. Think of a rare event in your field that is undervalued. How could you position yourself to benefit from it?

  3. What emotional biases make it difficult to bet on rare events?

CONTINUE THE CONVERSATION

Source texts

  • Fooled by Randomness The Hidden Role of Chance in the Markets and in Life (Nassim Nicholas Taleb)
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