The market returned to a limited buying mood after the U.S. central bank further reduced its appetite for bonds and mortgages, its effort to keep the cost of money low. The Nasdaq composite snapped a mild four-day losing streak Wednesday with a 0.5% advance in lower volume. That gain nearly recouped all of the prior four sessions’ worth of losses. But the S&P 500 showed that the institutional crowd wasn’t exactly buying with serious conviction.