NEW YORK—Wall Street stormed back this week after absorbing a long-awaited rate hike from the Federal Reserve, leaving investors to determine whether stocks are set for a sustained rebound or more turbulence. Following a months-long drubbing, the S&P 500 delivered its best weekly gain since November 2020 as investors cheered increased clarity on monetary policy and an encouraging assessment of the U.S. economy from the Fed. The surge cut the index’s year-to-date losses by nearly half, though it is still down 6.7 percent for 2022 after falling into a correction last month. Whether to hop on board the rally is a thorny question in a market that still faces its share of risks—chief among them the hawkish rate hike path the Fed unveiled on Wednesday and geopolitical uncertainty over Russia’s invasion of Ukraine. Still, some big banks believe the worst may be over, for now. Strategists at UBS Global Wealth …