In the last three days oil prices have fallen by roughly $10 a barrel. Many analysts say slackening demand, or the threat of it, is the main culprit.
But another force could be at work in the background. Last week various analysts said there was talk that Mexico, the world's fifth largest oil producer, was hedging its bets - the country was said to be signing contracts to deliver oil several years into the future at today's prices. Essentially, it was betting oil prices have peaked.
"This is a smart move," said Phil Flynn, senior market analyst at Alaron Trading in Chicago, who also thinks there's a good chance prices have peaked. "If I were an oil producer, I'd want to lock in these prices."
Analysts say if other oil producers follow suit and lock in future contracts, that could be one thing that would cause oil prices to fall, far and fast.
But it's hard to tell if that's happening because information about who is buying what is kept private for competitive reasons.
"I don't know who else is doing it," said Nauman Barakat, an energy trader at Macquarie Futures, and one of the traders who mentioned the Mexico news in a research note. "There's been a lot of talk, but it's kept very confidential."
