This whole meme stock thing has me rattled.  Investing used to make sense. It used to be that you could be fairly sure a stock price was accurate — in other words, that it represented the present value of future cash flows. A hundred years of evidence said so. Then WallStreetBets and Robinhood and crypto came along. Gamestop went up 50x, not because its prospects improved, but because a load of boyos on Reddit agreed it would be fun to pump it up. Even more unsettling, the Gamestop share price stayed high, even after the joke was over. It’s still worth about…