Like nature vs nurture, there have been seesaw arguments blaming either demand or speculation for higher oil prices. I've tended to blame demand while allowing that speculation plays a role. But in his July 6th Peak Oil Review, Tom Whipple noted:

"On Tuesday prices jumped to $73 a barrel when a rogue trader in London, acting without authorization, amassed huge positions in Brent crude, losing his firm $10 million in the process."

Reuters has more on that trader and the brokerage.

But Whipple also notes:

"The boss of Steve Perkins, the broker at the heart of a rogue oil trading scandal that rocked oil markets this week, issued a bullish report suggesting prices could go higher only hours after Mr. Perkins made the unauthorized trades that caused prices to spike. The disclosure raises further questions about internal controls at PVM Oil Associates, the world's largest oil brokerage."

McClatchy reports that the CFTC is trying to shine some light on oil speculators:

Regulators aim to curb speculators' influence on oil prices

"The Commodity Futures Trading Commission on Tuesday will announce that it'll begin publishing how much hedge funds and other big financial firms are trading in oil and other commodities, with an eye toward curbing what critics say is speculation that pushes prices up."

"The CFTC currently publishes weekly data that lumps some of the big financial firms' transactions in with those done by so-called commercial users -- airlines, refiners and others who actually use the oil. Critics argue that leaves regulators and the public unaware of how much oil prices are being influenced by speculation."

The speculation they speak of:

"... big Wall Street firms such as Goldman Sachs, Morgan Stanley and others, which have been exempted from limits on how much they can trade."

"... the practice by pension funds and big university endowments to invest in commodity indexes, a practice called index investment. ... These investors buy a range of commodities, including oil, and then hold the contract as if it were stock in a company whose share price will rise over time."

Score one for the speculation-blamers, but if nothing else, greater transparency could clarify the role of speculation vs the fundamentals of supply and demand.