Plus, if you're an insurance company in a hurricane zone, you carry a "megacat" (a catastrophic event insurance which is rather larger than most consumer grade policies, to put it mildly) policy underwritten by, most of the time, Berkshire Hathaway. If you sustain $1 billion in claims then you call up Warren Buffet and say "Sorry Warren, we just won our bet and will be needing those premiums back, and quite a bit more." and he'll say "Ah, shucks, guess I don't crush the market quite so thoroughly this year. Oh well, I still get to keep all of my winnings from investing the float in good years."