U.S. stock mutual funds fell for the first time in six weeks. The average U.S. diversified stock fund fell 0.58% in the latest week ended Dec. 4, according to Lipper Inc. That trimmed their year-to-date gain to 7.36%. U.S. funds held up a little better than world equity, which fell 1.35%. That shaved their year-to-date gain to 0.15%. S&P 500 funds, which track the broad stock market index, fell 0.01%.