U.S. crude were slightly higher in volatile trade on Monday, after weakening on concerns that a rally that had sent price to their highest since December 2014 had run out of steam.
Speculators currently have a record net-long position on the market, with bullish bets outweighing bearish ones.
"At these levels, the market requires a steady drumbeat of positive information, and without that, its hard to attract new longs to the market," said Gene McGillian, director of market research at Tradition Energy.
U.S. crude ended Monday's session up 25 cents at $63.62, having also hit its highest since December 2014 last week.
Brent crude was up 24 cents at $68.85 a barrel by 2:06 p.m. ET. Brent had hit $70.37 on Jan. 15, the highest since December 2014.