Circuit Breaker for the third time in six sessions

S&P 500 drops 11%, extending losses after 15-minute trading halt

The S&P 500 dropped 11.4% while the Dow Jones Industrial Average fell 2,700 points, or 11.7%. The Nasdaq Composite traded 11.2% lower. Those losses put the major averages on track for their worst day since the “Black Monday” market crash of 1987. They also eclipsed the steep decline seen on Thursday. 

https://www.cnbc.com/2020/03/15/traders-await-futures-open-after-fed-cuts-rates-launches-easing-program.html