U.S. stocks finished Monday's session significantly lower even after the Federal Reserve unveiled extensive new measures to support the economy amid the COVID-19 crisis.
The Dow Jones Industrial Average shed 582.05 points, or 3.04 percent, to 18,591.93. The S&P 500 decreased 67.52 points, or 2.93 percent, to 2,237.40. The Nasdaq Composite Index erased 18.84 points, or 0.27 percent, to 6,860.67.
Shares of United Technologies plunged 9.18 percent, leading the losses in the Dow. The index traded about 960 points lower at one point during the session. Boeing shares soared more than 11 percent, the best-performing stock in the 30-stock index.
Ten of the 11 primary S&P 500 sectors ended lower, with energy down 6.65 percent, the worst-performing group. Consumer discretionary rose 0.35 percent, the only gainer among the groups.
The Federal Reserve announced earlier in the day that it will purchase U.S. treasuries and agency mortgage-backed securities with no limit to help markets function more efficiently amid coronavirus uncertainty.
"The coronavirus pandemic is causing tremendous hardship across the United States and around the world," the Fed said in a statement Monday morning.
"While great uncertainty remains, it has become clear that our economy will face severe disruptions. Aggressive efforts must be taken across the public and private sectors to limit the losses to jobs and incomes and to promote a swift recovery once the disruptions abate," said the U.S. central bank.
Earlier this month, the Fed made an unprecedented second emergency rate cut over just a two-week period, bringing the benchmark rate to near zero. It also launched a massive quantitative easing program, pledging to boost its bond holdings by at least 700 billion U.S. dollars as a means to keep long rates down and provide liquidity into capital markets.
Wall Street finished the past week with massive losses as investors grappled with fears over potential economic damage by the coronavirus pandemic.
For the week ending March 20, the Dow shed 17.3 percent, the S&P 500 fell 14.98 percent and the Nasdaq lost 12.64 percent. The major averages had their worst weekly performances since the global financial crisis in 2008.