They expire today. That's 17 million barrels. From FT Alphaville:
A crude correction
Brent crude oil was trading at $70.02 on Monday morning; Nymex WTI crude, meanwhile, was trading at $66.08.
That is almost a $4 per barrel spread between the two contracts — its widest since mid-February when storage at Cushing, Oklahoma, the physical delivery point for Nymex traded WTI crude, peaked and caused numerous analysts to question the viability of the Nymex contract.
The downward correction in WTI to $66 per barrel from over $70 per barrel levels this month, meanwhile, came just as macroeconomic news was actually looking a bit more bullish....MORE