Source: https://mochatrade.com/learn/glossary/circuit-breaker

# Circuit breaker (US)
URL: https://mochatrade.com/learn/glossary/circuit-breaker
Last modified: 2026-10-17

A US circuit breaker halts trading. Market-wide, an S&P 500 fall of 7% or 13% stops all stocks for fifteen minutes and 20% ends the day; single stocks pause for five minutes at [the edge of their price band](https://mochatrade.com/learn/us-market-structure/how-us-stock-prices-form). Market-wide breakers belong to [the shocks lecture](https://mochatrade.com/learn), and [a contract on a frozen stock](https://mochatrade.com/support/what-is-a-perpetual-contract-and-does-it-expire) keeps trading.

## Related terms

- S&P 500: https://mochatrade.com/learn/glossary/sp-500
- Price band (discovery bounds): https://mochatrade.com/learn/glossary/price-band
- Gap up and gap down: https://mochatrade.com/learn/glossary/gap-up-and-gap-down
- Settlement (T+1 in US): https://mochatrade.com/learn/glossary/settlement
- Limit order: https://mochatrade.com/learn/glossary/limit-order
- Trading halt: https://mochatrade.com/learn/glossary/trading-halt

Educational content only. Not investment advice. Leveraged products magnify losses as well as gains.