Stocks moved higher at Thursday's opening bell as the focus shifts away from worries in Greece to domestic earnings and economic data. Before the bell, investors were greeted with a mixed bag of data. Weekly jobless claims came in stronger than expectations at 278,000 but productivity fell more than estimated in the fourth quarter, shrinking by 1.8% rather than rising by 0.1%. You may want to be even more careful when you tweet. Twitter (TWTR) has reached a deal with Google (GOOG) to make tweets more searchable online. It is an end of an era at the CME (CME). The company said it will close most of its trading pits in favor of electronic trading.