The OPEC trade is back, and Saudi Arabia is in the driver’s seat.

Just before the de facto OPEC leader doubled down on its plan to drain the oil glut, propelling Brent crude prices beyond $60 a barrel for the first time since 2015, hedge funds were almost as bullish on the global benchmark as they’ve ever been. Short-sellers retreated to levels last seen in February, when OPEC production cuts were fueling an oil price surge.

Saudi Crown Prince Mohammed bin Salman said in an interview with Bloomberg that “of course” he wanted to prolong the Organization of Petroleum Exporting Countries’ output-reduction deal into 2018. That was after Russia’s President Vladimir Putin said an extension should run through at least the end of next year. With the leaders of the world’s two biggest oil-exporting countries on board, an agreement is all but certain at a meeting in Vienna next month.

“We have evidence that people are positioned long into OPEC in November. The consensus trade on the street is that they’ll extend cuts,” Chris Kettenmann, chief energy strategist at Macro Risk Advisors LLC, said in an interview in New York. Prince Salman showing support has led to more seriousness around a potential extension of cuts and “it makes it very hard to be aggressively short.”

The fundamentals are looking brighter, too. U.S. crude inventories are near the lowest levels since January 2016. Saudi Arabia’s minister of energy and industry, Khalid Al-Falih, said oil demand is more resilient than people think, and Statoil ASA’s Chief Executive Officer Eldar Saetre said the oil market is “definitely balancing.”

There’s a stronger belief that the “supply-demand set-up has turned the corner, particularly with the push by the Saudis to keep the deal going and to drain global inventories,” John Kilduff, a partner at Again Capital LLC, a New York-based hedge fund, said in a telephone interview. “It’s worth betting that prices will go higher.”

Things started going south in the oil market in March as concern over rising U.S. stockpiles overshadowed confidence in OPEC’s efforts. Hedge fund bets and rising futures indicate that the confidence is coming back.

Hedge funds boosted their Brent net-long position -- the difference between bets on a price increase and wagers on a drop -- by 2.6 percent to 506,737 contracts in the week ended Oct. 24, according to data from ICE Futures Europe. That’s close to a record at the end of September and the previous high in February. Longs increased by 1.5 percent, while shorts slid 6.6 percent to the lowest since February.

The WTI net-long position rose by 7.2 percent to 234,878 futures and options, the first increase in four weeks, the CFTC data showed. Shorts fell 4.2 percent, while longs rose 2.7 percent to the highest level since April.

In the fuel market, money managers boosted their net-long position on benchmark U.S. gasoline by 11 percent, with long positions rising to the highest level in more than three years. Meanwhile, the net-bullish position on diesel increased 0.8 percent.

Front-month Brent contracts have been trading at a premium to later-dated contracts, a market structure known as backwardation that indicates strong demand and tight supplies. This is a shift away from contango, typical of a glut, that had loomed over the market for the past two years. WTI is also in backwardation in some areas of the futures curve.

“People are starting to think that the global inventory situation is better than they thought,” Michael Lynch, president of Strategic Energy & Economic Research in Winchester, Massachusetts, said by telephone. “The contango is getting very small, which suggests the markets perceive we’re a lot closer to being rebalanced than people had thought earlier.”

Yet, optimism around surging oil prices comes with risks. U.S. crude output remains above 9.5 million barrels a day and rose by the most since 2012 last week.

“My concern is what happens now that we’re getting to these price-highs where we’ve typically seen a supply response,” Rob Haworth, who helps oversee $142 billion in assets at U.S. Bank Wealth Management in Seattle, said by telephone. “Fundamentally, you should see a supply response and that’s going to make it tougher for these bulls to hang in there.”