During the regular hours of 9:30 a.m. ET to 4 p.m. ET, trading in equities may be paused market-wide if declines in the S&P 500 trigger a "circuit breaker." These occur when the benchmark index ...

Stocks were falling sharply again on Friday. Watch this level for a circuit-breaker to be triggered. - Getty Images/iStockphoto The market sell-off tied to President Trump’s “reciprocal ...

This means of interruption soon became inadequate and special devices called circuit breakers had to be developed. The basic problem has been to control and quench or extinguish the high power arc, ...