熔断
Circuit breaker
美国时间3月9日，美国三大股指开盘暴跌，其中标准普尔500指数迅速下跌超过7%，触发市场熔断机制，市场交易停止15分钟。这也是2008年金融危机后美股的首次熔断。当地时间12日，标准普尔500指数开盘后再次迅速下跌超过7%，触发熔断。这是美股本周第二次出现熔断。所谓熔断机制，指在交易过程当中，当价格波动幅度达到某一限定目标时，交易将暂停一段时间，防范恐慌情绪进一步扩散给市场带来更大冲击。
The S&P 500 fell by seven percent upon opening on Monday, triggering a circuit breaker that halted trading for 15 minutes for the first time since the 2008 financial crisis. The S&P 500 declined 7 percent shortly after the opening bell on Thursday, triggering a key circuit breaker. It was Wall Street's second 15-minute halt this week. The circuit breaker mechanism refers to measures adopted by stock exchanges to temporarily halt trading to avert panic selling by investors after the stock index has fallen a certain percentage.
马上学：熔断机制的英文是circuit breaker mechanism，其中，circuit breaker在电工学里就是断路器的意思。当电路中出现短路时，断路器会立即断开电路，保护负载的安全。