They don&#x27;t stop people from selling. Circuit breakers are useful for one-time flukes (e.g. Flash Crash) but for sustained downturns they can actually make things worse.<p>If you think you _may_ want to sell at all tomorrow but also think a circuit breaker could trigger, you&#x27;re going to sell first thing in the morning. So will everyone else.<p>The circuit breaker can actually trigger a worse panic as investors all try to squeeze in sell orders at once. This triggers the circuit breaker, confirming everyone&#x27;s fears, and starts again the next day.