U.S. stock futures signal no follow through By Steve Goldstein, MarketWatch Last update: 5:49 a.m. EST March 5, 2009 LONDON (MarketWatch) -- U.S. stock futures failed to extend gains Thursday following a rare up day, with disappointment over a lack of new Chinese spending dampening sentiment. S&P 500 futures (SPY SPDR S&P 500 ETF News , chart , profile , more Delayed quote data Add to portfolio Analyst Create alert Insider Discuss Financials Sponsored by: SPY) slipped 7.3 points to 701.10 and Nasdaq 100 futures (QQQQ PowerShares QQQ News , chart , profile , more Delayed quote data Add to...