David Einhorn

We try not to have many investing 'rules,' but there is one that has served us well: If we decide we were wrong about something, in terms of why we did it, we exit, period.

The enthusiasm for Tesla and other bubble-basket stocks is reminiscent of the March 2000 dot-com bubble. As was the case then, the bulls rejected conventional valuation methods for a handful of stocks that seemingly could only go up. While we don't know exactly when the bubble will pop, it eventually will.