See also: Oil’s Remarkable Rebound From a Year of Catastrophe

Top independent trader Vitol SA, however, joined with rival Gunvor Group Ltd. in expressing caution about the recent surge in prices, while a technical indicator is showing that oil is overbought and due for a correction.

Oil has rallied since the end of October amid Covid-19 vaccine breakthroughs and after Saudi Arabia pledged to deepen output cuts. OPEC+ has vowed to quickly clear the surplus left behind by the pandemic, but there are still concerns about near-term demand, with a new virus variant spreading in the U.S. and other regions across the world grappling with lockdowns.

“The fundamental picture of demand improvement and discipline on the supply side suggests there is clear upside for the market,” said Michael McCarthy, chief markets strategist at CMC Markets Asia Pacific in Sydney. “OPEC+ discipline has been a key to the gains.”

Brent’s prompt timespread was 27 cents in backwardation — where near-dated prices are more expensive than later-dated ones — compared with a 7-cent contango at the start of the year.

See also: Oil’s Recovery Is Too Fast for Its Own Good: Julian Lee

The market is “getting ahead of itself in terms of a post-vaccine euphoria,” Mike Muller, the head of Vitol’s Asian operations said Sunday in an interview with Dubai-based consultant Gulf Intelligence. Gains beyond $60 a barrel are unlikely because that would prompt energy companies to ramp up production, Gunvor Chief Executive Officer Torbjorn Tornqvist said on Friday.