Activision Blizzard (ATVI) moved higher ahead of its induction into the S&P 500 Friday afternoon. The company will replace Pall Corp (PLL) which is being acquired by Danaher (DHR). Stocks closed out a volatile week narrowly mixed, but managed to eke out gains over the period since Monday. Markets have moved erratically on fears over China's economy and concerns the Fed would hike rates despite these worries. Crude oil pulled off another major rally on Friday following a jump of more than 10% a day earlier. West Texas Intermediate closed with a weekly gain of nearly 12%, its first in ten weeks and best in six years. GameStop (GME) tumbled after third-quarter guidance caused a downgrade to SELL at analyst firm Benchmark. Analysts said the brick-and-mortar retailer will face increasing challenges as consumers buy video games online.