There's an alternative explanation: if you're good enough at convincing me to invest with you, you'll do the same with others. As long as I'm in early, you will

There's an alternative explanation: if you're good enough at convincing me to invest with you, you'll do the same with others. As long as I'm in early, you will make me money, even if I know the house of cards will eventually crumble. By then, I won't be a bag holder. (Probably.) I.e. greed and pride/hubris. The idealist image is just the current behavior that the investor expects will attract subsequent investors. This would explain bubbles much better than "rich people seem to be taking random walks." Edit: A.k.a. https://en.wikipedia.org/wiki/Greater_fool_theory https://en.wikipedia.org/wiki/Greater_fool_theory, though my point is it's not driven by foolishness.