But many investors and others may not know what the market circuit breaker is and why it is so important. What is a market circuit breaker? How does a circuit breaker work? What are single-stock ...

The Dow plunged 1,089 points Monday on the open, prompting investors to ask us, "Will the stock market shut down today?" You see, if markets fall far enough, circuit breakers kick in and halt trading.

U.S. stocks had gone more than 20 years without a market-wide trading halt. We've now tripped the so-called circuit breakers two times in four days. On Monday, March 9, the S&P 500 fell 7% within ...

Six minutes after trading began on the New York Stock Exchange on Monday, it was suddenly halted. That's when the S&P 500 index had plummeted 7% and marketwide circuit breakers kicked in. Trading ...

Six minutes after trading began on the New York Stock Exchange on Monday, it was suddenly halted. That's when the S&P 500 index had plummeted 7% and marketwide circuit breakers kicked in. Trading ...