By David Randall NEW YORK (Reuters) -Expectations of a hawkish Federal Reserve are dimming Wall Street’s outlook for stocks, with some investors now bracing for a potential bear market in the benchmark S&P 500 index. A bear market – often thought of as a 20% or more decline from a high – would mark the end of the pandemic-era rally that sent stocks to record levels on the back of unprecedented stimulus from the Federal Reserve. After falling 2.5% Monday, the S&P 500 was recently around 16% below its high reached Jan. 3 as it struggles through the worst four-month start to a year since 1939. Th…