What Keeps You Awake at Night?

Zonesree: Very low interest rates are more of a long term, because if you get a portfolio chock full of 4% mortgages or something of the sort, and then you had a huge move upward. That could be quite painful for some period of time, no matter what you've done in the way of hedging. Charlie? I've got nothing to add. Jane Bell Des Moines: Since I became a Berkshire Hathaway shareholder, I've been coming to these meetings. This is my second. Mr. Buffett, from your perspective as an investor, what keeps you awake at night?