LONDON (Bloomberg) -- Oil slipped from a three-year high amid speculation that a surge in hedge-fund buying had pushed prices up too quickly.

U.S. crude futures lost 0.4% while in London Brent retreated from $70/bbl, a level it crossed last week for the first time since 2014. Money managers increased their bullish bets on U.S. crude to the highest in more than a decade, according to the Commodity Futures Trading Commission on Friday. Futures’ 14-day Relative Strength Index also suggested prices might have overshot.

Oil has extended a two-year rebound as the Organization of Petroleum Exporting Countries and its allies trim production to drain a global glut. Yet there’s concern that rising prices may spur output in the U.S., where the rig count rose by 10 last week. Record bets by speculators have left the market vulnerable to a pullback, according to Commerzbank AG.

“The speculative overhang on the oil market has grown,” said Carsten Fritsch, an analyst at Commerzbank in Frankfurt. “We therefore expect prices to correct” as “inventory trends shift and attention is focused more on growing U.S. oil production.”

West Texas Intermediate for February delivery was at $64.05/bbl on the New York Mercantile Exchange, down 25 cents, at 2:05 p.m. London time. There was no settlement Monday because of the Martin Luther King Jr. holiday in the U.S., and all transactions will be booked Tuesday. Futures closed at $64.30 on Friday, the highest level since December 2014.

Brent for March settlement dropped 81 cents to $69.45/bbl on the London-based ICE Futures Europe exchange after adding 0.6% on Monday to close at the highest since December 2014. The global benchmark crude traded at a premium of $5.51 to March WTI.

Hedge funds increased their WTI net-long  position by 10% to 437,770 futures and options during the week ended Jan. 9, according to data from the CFTC. The Brent net-long position climbed 1.5% to a record 574,152 contracts, ICE Futures Europe data show.