I wasn't joking.
> If it were, as Buffett has noted frequently, his success would have been completely impossible. Indeed, the most money is made from the highest inefficiencies.
Survivorship bias? I don't know, but in any case market efficiency is a very general claim, it doesn't rule out some "special" people with innate talent to predict future prices.
>And there's no inherent or guaranteed mechanism that drives under or over valued stocks back into any theoretical fair value line. Stocks are governed by human judgment ultimately - which typically swings emotionally to extremes - there's nothing efficient about that.
Just empty rhetoric. Look into the literature of econometric tests of the efficient market hypothesis.