That meant that for the next half-hour, no contracts could trade below that level.

Earlier in the day, the contract had traded as high as $15.75.

The contract traded as low as $4.13 during the session.

In the second week of February, only 26 contracts traded.

The contract traded as high as a record $1.10 before easing.

But 130 contracts traded late last week, then 140 more on Monday and a stunning 1,708 yesterday, at prices up to $1.375 an option.

At one point the contracts were trading at $13.25 a barrel.

But he said it would break even after reducing its expenses if 450,000 contracts trade each day.

Exchange officials reported that trading was stopped 10 times during the day and that the contract traded only intermittently in the afternoon.

For the past 15 years, he said, these contracts traded in a narrow range of around $20 a barrel.