I suspect that that fact and our beliefs around it are being reflected in market prices, albeit with some heavy discounting for the uncertainty inherent in there still being so many companies out there.

So many people's first instinct to respond by buying more shares of that company, thereby driving its price and market cap higher. That's a reaction that implies that we think that the general trend is toward Buy-n-Large. If we expected regression to the mean to be the driving phenomenon, then we'd be more likely to respond by selling.

(Disclaimer: I'm not suggesting that's actually how things work, just that a lot of us behave as if we think that's how it works, or should work.)