Oil swung between gains and losses as speculation mounted about OPEC’s decision on production policy.

Futures rose 0.6% in New York after jumping 4.2% on Wednesday, the biggest gain since the attacks on Saudi Arabia’s energy facilities. Saudi Arabia is offering fellow OPEC+ members a quid pro quo to stop cheating in exchange for further production curbs. An OPEC+ committee is said to be debating a 500,000 barrel a day cut to output, though the group was already pumping that much below its target in October.

Crude rose on Wednesday as the U.S. and China moved closer to agreeing on the amount of tariffs that would be rolled back in an initial trade deal, as their standoff continues to dent global demand. While Iraq had earlier backed away from a proposal for steeper production curbs, other ministers inidicated a preference for deeper cuts upon arrival at OPEC. The precise terms of any proposed deal remain unclear, and market watchers should be cautious of any announcement.

“It’s OPEC day and there is a sense of cautious optimism in the air,” PVM Oil Associates analyst Stephen Brennock wrote in a report. “There is a consensus among market players that the oil cartel will deepen supply curbs in order to avert a supply imbalance in the new year.”

West Texas Intermediate for January delivery rose by 36 cents at $58.79 a barrel on the New York Mercantile Exchange as of 09:11 a.m. local time. Brent for February settlement added 57 cents to $63.57 a barrel on the London-based ICE Futures Europe Exchange. The global benchmark crude traded at a $4.91 premium to WTI for the same month.

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The OPEC meeting in Vienna will be the first since Saudi Oil Minister Prince Abdulaziz bin Salman took the top job. He said he felt good about the meeting on Thursday. United Arab Emirates Energy Minister Suhail Al Mazrouei wouldn’t confirm which proposals will be discussed.