During US trading hours (Cash), these are the levels for the various circuit-breakers to hit:
Level 1: 7% fall to 2352.14 before 15:25EDT/19:25GMT will prompt a 15-minute pause.
Level 2: 13% drop to 2200.39 before said time will introduce another 15-minute pause.
Level 3: 20% decline to 2023.35 within the time will shut the markets
Will we see the first Level 2 trigger today?