Many people trade poorly—not because of cognition, but because of a sense of luckiness.

If you run two stores at the same time, one store is consistently profitable while the other is consistently losing, then at this point he knows to close the losing one.

But if you switch it to buying two coins—one keeps rising and the other keeps falling—then at this point he will sell the one that’s rising, and hope that the other that’s falling will bounce back to break even.

Someone with even stronger luckiness will take the money from selling the rising coin and buy the falling one.