The S&P 500 closed at its highest level ever Tuesday, capping a remarkable rebound fueled by unprecedented government stimulus and optimism among investors about the world’s ability to manage the coronavirus pandemic. The benchmark U.S. stock index surpassed its prior record of 3386.15 from Feb. 19, erasing a historic plunge during February and March that ended the longest-running bull market in history. The S&P 500 is now up about 5% this year. …