U.S. Stocks Rebound With Health Care Adding Boost: Markets Wrap (Bloomberg) -- U.S. stocks rallied as investors saw glimmers of optimism in efforts to deliver rapid testing for the new coronavirus. The dollar rose. The S&P 500 Index climbed for the fourth time in five days, rising 17% over the last week, with health-care shares among the biggest gainers. The Nasdaq 100 advanced nearly 4%, leading the rebound among benchmarks from Friday’s losses.