The S&P 500 ended down on Tuesday, with losses in Apple and Amazon ahead of an upcoming speech by U.S. Federal Reserve Chair Jerome Powell that could provide hints about magnitude of future interest rate hikes.
Investors also focused on recent protests against COVID-19 curbs in China, including at the world's biggest iPhone factory.
Apple's (AAPL.O) stock dropped 2.1%, down for a fourth straight session.
Powell is due to speak at a Brookings Institution event on Wednesday about the outlook for the U.S. economy and the labor market. Investors will be looking for clues about when the Fed will slow the pace of its aggressive interest rate hikes.