During periods of volatility, a market-wide circuit breaker can be triggered, causing halts to all US exchanges and venues.
These are measured against the previous days S&P 500’s closing price. If the price difference is more than the values listed below, a halt will occur.
Circuit Breaker Levels
Level 1 - 7%
Level 2 - 13%
These circuit breakers can only be triggered between 9:30 am and 3:25 pm. Once triggered, they halt trading for a minimum of 15 minutes.
Level 3 - 20%
This circuit breaker halts trading for the rest of the day and can be triggered anytime.
What does this mean for me?
During a halt, the US markets are closed, and orders can not be processed until the market re-opens. It's similar to placing an order at 10 AM Australian time, your order will be processed at market opening.
Non-executed orders will remain in a pending state until they are cancelled, executed or expired.
You are also able to cancel any orders still pending at any time during the halt.