The circuit breakers are set to halt trading when the Dow is down 10 percent or more during the day.

You halted trading while you demanded they fix up their books.

The system was first set up to halt trading if the Dow fell by so many points, say 350.

We halted trading and subsequently determined there was no regulatory issue involved.

Nasdaq will cooperate with a plan to halt trading in volatile periods.

The exchange did not halt trading in the security after the company said it would be worthless.

Not part of decision by exchanges to halt trading in stock index futures.

The Moscow stock exchange plummeted 10 percent, prompting officials to halt trading.

The officials received notice of the disruption and decided to halt trading four minutes before the official close.

If a 10 percent fall came after 2:30, it would not halt trading.