By Devik Jain and Echo Wang (Reuters) – Wall Street stocks ended higher on Tuesday after a choppy session in which each of the major indexes fluctuated between gains and losses as a key meeting of the Federal Reserve got under way. Investors picked up shares of financials and technology companies ahead of Wednesday’s expected announcement by the Fed. Nine of the 11 major S&P 500 sectors rose, with energy and financials up 2.9% and 1.3%, respectively. The S&P 500 banks index gained 2%, with Citigroup Inc climbing 2.9%. The U.S. central bank kicked off its two-day policy meeting on Tuesday. Trad…