Warren took a lot of heat in the 1990s for not investing in the tech sector. But hey, he didn't feel comfortable with tech, so he didn't invest in it. One way to look at this is: "ha ha, what a dinosaur, he sure missed out, and now he's, uh, only the richest person in the world by a small margin." But another, more accurate way to look at it is this: he's the richest person in the world, you asshole. When he gives you investment advice, take it!