OPEC would try to talk down an oil rally above $70 a barrel to cushion the impact on the global economy and rival supplies, according to Goldman Sachs Group Inc.

Oil has climbed to a three-year high above $69 in London amid OPEC production cuts, growing demand and political risks to supply. If prices keep rising, OPEC could see some unwelcome developments, such as greater investment by competitors including U.S. shale drillers, or central bank interventions to temper inflation, Goldman said.

“OPEC members do not want to see that,” Jeff Currie, the bank’s head of commodities research, said in a Bloomberg television interview from Frankfurt. “We’ll see more noise and rhetoric if prices trade above $70 a barrel in coming days to push this market back down.”

The Organization of Petroleum Exporting Countries formed an alliance with Russia in late 2016, cutting their output to end a glut that has weighed on prices and battered their economies. The coalition has agreed to press on with the curbs until the end of the year to eliminate the remains of the oil surplus.

Yet there are signs the cartel is growing uncomfortable with the consequences of higher prices. Iranian Oil Minister Bijan Namdar Zanganeh said Tuesday that OPEC didn’t want oil above $60 because it might provoke too much U.S. shale growth. Fellow members such as Iraq and Nigeria have made similar warnings.

America may challenge both Saudi Arabia and Russia as the world’s top crude producer, with its output headed for 11 million barrels a day in late 2019, the U.S. Energy Information Administration said Tuesday.

Further price gains would bring more money to the sector, closing the “window of opportunity” that OPEC has enjoyed while U.S. explorers have had limited access to new capital following disappointing results, Currie said.

Goldman sees opportunities for investors from the misalignment between short- and long-term prices. Spot prices are being supported by the strongest global economic conditions since the start of the commodities boom in 2004, while later-dated prices are being damped by the prospect of increasing U.S. crude production, Currie said.

Investors can gain by buying and holding earlier-dated contracts, profiting as they “roll” the position from one month to the next, Currie said.