Major averages took it on the chin Thursday as media stocks and several leading growth stocks sold off. The Nasdaq pierced its 50-day moving average, falling 1.6%, while the S&P 500 closed just above its 200-day moving average, ending with a loss of 0.8%. The Dow Jones industrial average gave up 0.7%. Preliminary data showed volume on the NYSE and Nasdaq coming in higher than Wednesday’s levels.