Stocks rallied in the last hour of trading Friday, but still finished down for the day as worries over Greece and China continued to plague the market. The Nasdaq and the Dow Jones industrial average lost 0.3%, while the S&P 500 dropped 0.4%. Volume was higher on the NYSE and Nasdaq exchanges, according to preliminary data in the stock market today were generally lower. The Shanghai Composite rose 2.4%, but other indexes fell.