Mr. Market

Biological Parallel

Male túngara frogs call for mates in the darkness, but females don't assess calls objectively—hungry bats eavesdropping on the same calls make certain frequencies lethal. A call valued highly when predators are absent becomes worthless when bats arrive, not because the frog's quality changed, but because the evaluator shifted. Graham's Mr. Market personifies this: intrinsic value stays constant while the market's assessment swings based on mood, creating mispricing for those who assess independently.