Shares of the United States Oil Fund (USO) are trading lower on the session by 0.06%, at $36.09. The ETF touched an intra-day high of $36.28 before pulling back into the EIA Weekly Inventory Report.

The Energy information Administration reported an increase of 2 million barrels for the week ending September 7th. The Street was looking for a decline of over 3 million barrels, so this was quite a surprise to traders.

October crude futures are currently off 0.12%, trading at $97.06.

There was a flurry of call activity in the USO earlier in the session, mostly on the sale side.

The heaviest action came on the December $38.50 strike, where 16,834 contracts were sold, on the bid, for $1.435. Volume on the strike has since risen to over 33,000 contracts; open interest is 23,741. The strike is now bid $1.37, at $1.39.

Another small trade occurred on the Dec $38.50 strike, where 2,414 contracts were sold, on the bid, for $1.38. This appears linked to fresh stock purchases at $36.21.

In other USO options news, the November $38 call was purchased 6,700 times, on the offer, for $1.12. Open interest on the strike was just 756 contracts. It is now bid $1.08, at $1.09.

The United States Oil Fund seeks to reflect the performance less expenses of the spot price of West Texas Intermediate (WTI) light sweet crude oil. The fund will invest in futures contracts for WTI light sweet crude oil, other types of crude oil, heating oil, gasoline, natural gas, and other petroleum based-fuels that are traded on exchanges.