alt Hacker News> Equity bubbles don't have to crash. Prices can just stagnate while profits catch up and multiples compress.
Is there is historical evidence for that? As someone who used to follow Jeremy Grantham a lot (he considered himself a "bubble historian"), IIRC every bubble he studied always mean reverted, and it usually (maybe always, can't remember) overshot on the downside during the correction.
> IIRC every bubble he studied always mean reverted
This really depends on how we're defining these things. Let's call a stock-market bubble a period of elevated multiples. That can mean revert by prices decreasing while earnings stay constant or by prices staying constant and earnings rising. (Alternatively, both earnings and multiples can rise and fall.)