Berkshire's results suggest the 93-year-old Buffett, one of the world’s most revered investors, is growing wary about the broader U.S. economy or stock market valuations that have gotten too high. The results were released on Saturday after a stock market selloff that pushed the Nasdaq into correction territory, while a weak jobs report sparked worries about U.S. economic activity and whether the Federal Reserve waited too long to cut interest rates.