Circuit breaker

A circuit breaker is a built-in pause that halts trading or contract activity when prices move too fast or something looks wrong. It matters because it gives exchanges and protocols a chance to stop panic selling, exploit drains, or oracle glitches before they cascade into bigger losses. Traditional stock markets use this idea too: the NYSE halts trading for 15 minutes if the S&P 500 drops 7% in a session. In crypto, some centralized exchanges pause withdrawals during extreme volatility, and certain DeFi protocols code in automatic freezes if a price feed jumps more than a set percentage in one block. It's a blunt tool, not a fix, but it buys time to check whether a crash is real or the result of a bug or attack.