circuit breaker
noun [ C ]
ukusa piece of equipment that stops the flow of an electric current, used to prevent damage to the wires and equipment that are connected to it:
If your internet access is out, it could be that a circuit breaker was tripped during a storm.
STOCK MARKET
a rule that temporarily stops trade on a stock market or closes it when prices go down to a particular level too quickly:
The New York Stock Exchange instituted circuit breakers to reduce volatility and promote investor confidence.
There are three circuit-breaker thresholds—10%, 20%, and 30%— calculated at the beginning of each quarter.