The company had taken out short positions, or bets that crude prices would fall, as a hedging strategy for oil it intended to move through a subsidiary's pipelines and sell to refiners, according to an affidavit filed in Delaware bankruptcy court by Terrence Ronan, SemGroup's senior vice president, finance.
Then, when oil prices rose, SemGroup moved to "cover" its short positions by taking out equivalent long positions, or bets that oil prices would rise.
Eventually, SemGroup was unable to put up collateral for its swelling bets and sold its futures account to Barclays Capital on July 16, according to the affidavit.
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One theory making the rounds in the market is that as SemGroup's long positions snowballed, so did the oil rally. SemGroup's rapid exit from the market removed a force for upward momentum when the market, under siege from negative U.S. economic indicators, needed it most.
"In the three days surrounding that transfer" to Barclays, crude futures "plunged $15.89...thus, with SemGroup removed from the market, crude oil has been free to fall," wrote Stephen Schork, editor of the Schork Report, a newsletter tracking the oil market.