Intel (INTC) was the worst performer on the Dow Thursday on fears of weakening demand following key supplier QLogic's (QLGC) quarterly sales warning. A China-inspired rally faded throughout the afternoon with investors showing increasing concern as Greece barreled toward its debt deadline. The S&P 500 added 0.2% and the Dow gained 32 points, both far from session highs of more than 1%. Uncertainty over Greece's future headlined the afternoon session as Athens approached a deadline in which to submit proposed spending cuts. The government is seeking a three-year loan from the eurozone to save it from bankruptcy and keep it in the euro. Walgreens Boots Alliance (WBA) topped the S&P 500 after beating quarterly estimates and naming Stefano Pessina as its permanent CEO.