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

If the average moved 200 points from the previous close, trading would be halted for 90 minutes.

If the average fell 150 points more that day, trading would be halted for two hours.

If the market falls another 150 points on the same day, trading will be halted for two hours.

If the average fell an additional 150 points on the same day, trading would be halted for two hours.

During the day, trading is halted for 30 minutes if the market drops 12 points.

However, in the second session, trading would not be halted.

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

When trading was halted on July 17, the shares were worth about $234 million.

The company's stock fell to $4.125 yesterday, off $1 a share, before trading was halted.