Reiterating his call to invest for the long haul, Buffett acknowledged that he doesn't know where the stock market will go in the next "10 days or a year or two years." But one thing he said he does know: "It's going to be higher 10 years, 20 years from now." "There will be hiccups from time to time in the economy," he cautioned. "[But] we'll do well over time."