The Federal Reserve delivered the emergency rate cut investors had been clamoring for at 10 a.m. on Tuesday. The market rally that followed lasted about 15 minutes.

By the end of trading on Tuesday, stocks were sharply lower and bond yields had plummeted to previously unthinkable lows, suggesting that there’s little the Federal Reserve can do to keep the coronavirus from hammering the U.S. economy.

The S&P 500 fell about 2.8 percent, undoing much of Monday’s 4.6 percent surge. The yield on the 10-year Treasury note dropped below 1 percent for a time.

Both moves suggest investors see growing threats to the outlook for economic growth and corporate profits over the next 10 months.