U.S. stocks plummeted Thursday morning, following sharp declines in futures and global markets overnight.

The S&P 500 fell 7 percent shortly after the market opened in the U.S., triggering a 15-minute “circuit breaker,” halting trading at the NYSE for 15 minutes.

Dow Jones Industrial Average also fell by more than 1,600 points, around 7 percent. The Nasdaq Composite saw a 7 decline as well.