If you want to stick it to speculators, the best way to do it is to wait until sentiment is extreme, then hike margins right before bearish supply data. That is precisely what has happened.

I discussed collapsing demand on May 6 in (please see Oil Consumption Demand Destruction vs. Speculative Futures Positions.

CME Doubles Daily Price Limits

Today we see Oil Drops Below $100 as U.S. Supplies Surge

Oil fell below $100 a barrel in New York and gasoline tumbled the most in more than two years after an Energy Department report showed that U.S. supplies surged and fuel demand slipped.

Crude dropped as much as 5.2 percent after the department said stockpiles jumped 3.78 million barrels to 370.3 million last week. Gasoline inventories unexpectedly increased 1.28 million barrels to 205.8 million, the first gain in 12 weeks. Total fuel consumption declined 0.9 percent to 18.2 million barrels a day, the lowest level since June 2009.

“We have a tremendous glut,” said Todd Horwitz, chief strategist at Adam Mesh Trading Group in New York. “The rally in commodities appears to be over. We’re going to see prices work their way lower in coming weeks.”

Crude oil for June delivery fell $5.13, or 4.9 percent, to $98.75 a barrel at 2:17 p.m. on the New York Mercantile Exchange. The contract slipped as much as $5.43 to $98.45. Prices are up 29 percent from a year ago.

Gasoline for June delivery dropped 25.9 cents, or 7.7 percent, to $3.1207 a gallon in New York. The contract declined as much as 9 percent, the biggest fall since Feb. 2, 2009.

CME Group Inc. suspended trading of gasoline, crude and heating oil on the Nymex for five minutes starting at 12:06 p.m., said Laurie Bischel, a spokeswoman for the exchange in Chicago. Trading was stopped after June-delivery gasoline fell 25 cents, the daily limit. Limits were widened to 50 cents a gallon for gasoline and heating oil and $20 a barrel for crude.
Double Limits on Heels of Margin Hikes

The Wall Street Journal reports Crude Tumbles As CME Margin Hike Spooks Investors
Crude futures fell sharply in Asia Tuesday as traders responded bearishly to an announcement by CME Group Inc. (CME) of an increase in margin requirements for oil contracts, whi