U.S. stock futures traded lower on Monday, pointing to a softer market open, hurt by uncertainty about interest rates ahead of a speech this week from new Federal Reserve Chairman Ben Bernanke. Tensions in Iran over its nuclear program also kept the market on edge, while shares of Web search leader Google Inc. declined in pre-market trading after Barron's business weekly said the stock could face a further 50 percent decline. Standard & Poor's 500 futures were down 1.4 points, below fair value, a mathematical formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures were down 17 points, and Nasdaq 100 futures were down 3 points. Google shares were down almost 4 percent before the Bell after Barron's said Google could fall if it faces mounting competition or fraud by users of its ad-buying system. Investors may have been selling stocks ahead of Bernanke's first appearance before the House Financial Services Committee later this week. Expectations have been mounting that the Fed will keep raising interest rates, further than originally hoped, which is making the stock market hesitant, an analyst said. "There's an unknown there. Lately the data is suggesting that what Wall Street assumed to be the end of rate hikes is not the end," said Andre Bakhos, president of Princeton Financial Group in Princeton, New Jersey. "The market is just a bit anxious over what he's going to say, so I think the market is discounting potential inflammatory statements."