Wall Street ended lower Tuesday with losses picking up within the final minutes of trading, as reports threw cold water on Moderna's COVID-19 vaccine candidate.
The Dow Jones was down about 1-and-a-half percent, breaking a 3-day streak of gains.
The S&P 500 closed one-percent lower and the NASDAQ ended half-a-percent down at 91-85.
Oil prices ended mixed Tuesday despite global supply cuts and signs of improving demand.
WTI was up 2-percent, but Brent Crude was down one-percent at 34-dollars 46 cents a barrel.