Mean reversion: Has AI abolished gravity for share prices?

HERE is a good phrase for suggesting a stock price has risen unsustainably: “Up like a rocket, down like a stick.”

It works nicely because gravity is an analogy commonly used in investment. Hence, all that “soaring”, “climbing”, “falling” and “plunging” which market reporters attribute to shares.

But “gravity” is just too widely understood to sound technocratic. So financial natives talk about “mean reversion” instead.