China risk has reemerged in the U.S. stock market — here’s how events may play out By: MarketWatch May 15, 2020 at 11:22 AM EDT Apple is a key stock to watch because it has such a heavy weighting in the benchmark S&P 500 Index. Read More >> Related Stocks: Alphabet-A Alphabet-C Amazon.com Apple Cisco Systems Facebook Microsoft Qualcomm, Inc.