LONDON—The U.S. dollar held below its 2-1/2 week high on Wednesday as risk sentiment stabilized before a Federal Reserve meeting where policymakers are widely expected to signal readiness to start raising interest rates from March. Markets have been on a rollercoaster ride this week as the combination of a hawkish Fed and slowing growth have unnerved investors, prompting them to dump high-flying technology shares and seek refuge in safe-haven assets such as the dollar. It briefly touched a Jan. 7 high of 96.30 against a basket of currencies on Tuesday before ending below that level. In early London trading, it was a shade higher at 96.08 with U.S. stock futures up more than 1 percent, indicating a stronger start on Wall Street. Citibank strategist Ebrahim Rahbari said broader risk conditions, investors’ appetite for riskier assets, such as stocks and emerging markets currencies, were playing a more important role for the …