If Wednesday was an example of stock proxies overcoming negative news, Thursday was shaping up as a session in which shares were unable to benefit from some positive developments. Despite better-than-expected retail sales data and some positive corporate guidance, major stock proxies couldn't sustain a midmorning rally and were lately trading south of breakeven.As of 2:18 p.m. EST, the Dow Jones Industrial Average was down 0.7% to 8528.53 after having traded as high as 8615.13 and as low as 8510.84. The S&P 500 was down 0.6% to 899.42 but off its earlier low of 897 while the Nasdaq Composite was lower by 0.3% to 1392.22 vs. its low of 1388.5. On the economic front, the government reported retail sales rose 0.4% in November and 0.5% excluding autos, both results were well in excess of consensus estimates of 0.3% overall and 0.2%, excluding autos. Separately, the Bank of Tokyo-Mitsubishi reported U.S. same-store sales rose 2% last week. On the micro front, Costco ( COST) reported fiscal first-quarter results in line with expectations but lowered its sales and earnings guidance for the remainder of the year. A much higher-than-expected jobless claims report -- initially rose 83,000 to 441,000 vs. estimates of 393,000 -- was an offsetting factor to the retail sales data, but considering the latter was presumably such a concern among traders on Wednesday, the market's tepid reaction was disappointing. Simultaneously, equity bulls were unable to parlay upbeat news from firms such as Ciena ( CIEN), Amgen ( AMGN) and Halliburton ( HAL) into anything more than gains for those names. In the midst of economic news flow generally weighted toward the positive, stocks were reportedly sluggish due to geopolitical concerns. Specifically, The Washington Post reported Iraq may have given chemical weapons materials to al Qaeda and various news outlets have reported North Korea is planning to restart a nuclear power plant that may be used for making weapons-grade uranium.