U.S. stocks traded sharply lower at Thursday's opening bell amid fears over the COVID-19 epidemic and questions about whether the efforts of government authorities will be enough to contain the disease and limit the economic damage it is expected to cause. The S&P 500 SPX, -0.84% was down 2.5% to 3,053. The Dow Jones Industrial Average DJIA, -0.46% retreated 729 points, or 2.7%, to 26,362, a day after the blue-chip benchmark climbed more than 1,200 points. The Nasdaq Composite COMP, -1.26% fell 2.4% to 8,803. California declared a state of emergency due to the epidemic, and U.S. airlines have scaled back their flight schedules in response to concerns over insufficient passenger demand. Policymakers are now freeing up funds to combat the virus, with U.S. lawmakers passing an $8 billion spending package on Wednesday. A reflection of the economic fears weighing on Wall Street, the 10-year Treasury note yield TMUBMUSD10Y, 0.680% fell to 0.936% on Thursday, within spitting distance of an intraday low of 0.918% set on Tuesday.