Trading volume has also been light, with many investors still on vacation. That also makes the market more susceptible to getting yanked around: With fewer shares trading hands, the market can be moved by relatively small trades.Last week, about 2.2 billion shares traded hands each day on average. Throughout the year, the average has been closer to 3.6 billion. The yield on the benchmark 10-year Treasury note rose to 1.74 percent from 1.70 percent late Friday. Some of the best-performing stocks for the year were those that had been hammered in 2011. Homebuilder PulteGroup, appliance maker Whirlpool and Bank of America all more than doubled over the year, after falling by double-digit percentages in 2011. Some of the worst performers of the year were Best Buy, Hewlett-Packard and J.C. Penney. All are struggling to keep up with competitors who have adapted more quickly to changing technologies and changing customer tastes. They were all up Monday, but were each down at least 45 percent for the year.