Dow Jones Industrial Average futures were lower by 1,040 points, or 4.5 percent, while the S&P 500 and Nasdaq Composite were down 4.7 percent and 4.5 percent, respectively.
The losses come after the Fed slashed its benchmark interest rate by 100 basis points to a range between zero and 0.25 percent and said it will buy $700 billion worth of Treasury securities in a new asset-purchase program.
President Trump called the emergency action "a big step" and said he would ease up on his criticism of the central bank.
In European trading, London's FTSE was down 7.5 percent, Germany's DAX plunged 8 percent and France's CAC dropped 10 percent.
In Asia, Japan's Nikkei was down 2.5 pecent, Hong Kong's Hang Seng fell 4 percent and China's Shanghai Composite dropped 3.4 percent.
Commodities were also lower with gold futures for April delivery trading down 0.8 percent at $1505 an ounce and West Texas Intermediate crude oil futures for May delivery off 5.7 percent at $30.28 per barrel.
As investors moved out of riskier assets they bought U.S. Treasurys. The flight to safety pushed the yield on the 10-year note down 19 basis points to 0.764 percent.
Heavy selling of equity futures follows the major averages all soaring over 9 percent Friday in response to Trump declaring the new coronavirus outbreak a national emergency and enlisting some of the nation's biggest companies, including Walmart and Google, to assist health officials in combating the virus and helping with procedures and testing.