Narrative fallacy
The urge to explain a price move with a coherent story: the explanation is assembled after the fact and turns the accidental into the inevitable.
How to read the number
The test is simple: would the same story serve for the opposite outcome. If it would, the explanation carries no information and only provides comfort.
When the metric lies
A headline of the form the market fell because of such-and-such is almost always assembled in hindsight: the causes of a move are not observable, only the trades are. Taken as fact, such an explanation becomes the basis of the next decision.
Also known as: story-driven explanation