Portfolio theory, anyone?<p>Investing isn't 'gotcha' politics or rhetoric. There's no reason why all a person's investments have to advance some unified self-consistent theory of the world. In fact, it's almost certainly better if they don't.<p>If an investor is choosing well, their investments altogether can be like a roulette wheel where red, black, and green all have positive expectations. No, they can't each come up at the same time, but that exclusivity doesn't make it irrational to bet them all simultaneously.