[Editor's note: The futures market reopened at 6 p.m. ET.]
The Dow Jones industrial average closed 4.6 percent lower Monday, or more than 1,100 points lower in its biggest points-drop ever.
Dow futures initially fell sharply in after-hours trading, as did S&P 500 futures. But futures were trading higher when the market reopened at 6 p.m., ET.
On Monday, the S&P 500 erased its gains for the year and closed 4.1 percent lower, its worst day in six years. There was no specific driver for the sharp decline.
Stocks extended last week's plunge that was fueled by worries about rising interest rates.