”We made some money on it,” Icahn said in an interview Friday with Bloomberg Television. “We did get a fair amount.”

The billionaire raider-turned-activist took advantage of the historic collapse in crude futures to supply his Midwestern refiner, CVR Energy Inc. He said CVR tried to purchase 1 million to 2 million barrels of oil when prices went negative in a technical quirk of futures trading that temporarily forced sellers to pay to have contracts taken off their hands.

It’s a role Icahn, a wily investor with gifted timing, has played before. In one of his more legendary trades, Icahn left Donald Trump’s election-night victory party in November 2016 to buy $1 billion of U.S. equity futures as stocks slumped in the early hours of the morning.

Monday presented a similarly rare and short-lived opportunity. With oil markets oversupplied and running out of storage space because of the coronavirus pandemic, at about 2 p.m. crude for May delivery fell below zero and began an unprecedented plunge to less than minus $40 a barrel. Investors with no use for the physical commodity and no place to keep it next month became increasingly desperate to unload contracts.

“You’ll never see that again in history,” Icahn said.

To be sure, CVR isn’t the only company that bought oil for less than nothing. From Wyoming to West Texas, the bids that refiners, traders and pipeline companies post every day for oil they buy out in the fields fell way below zero, mirroring the plunge in futures prices.

The profitable trade offset losses on some of Icahn’s other oil bets. Occidental Petroleum Corp., the company he battled for almost a year before settling the proxy contest last month, has fallen 67% year-to-date.

Icahn was critical of financing that Occidental obtained from Warren Buffett for its purchase of Anadarko Petroleum Corp. Now that the oil slump has left it so strapped, Occidental had to issue $257 million in stock to pay Buffett his special dividend.

CVR has held up better, down only 54% this year. Based in Sugar Land, Texas, it refines crude into gasoline and other fuels at refineries in Coffeyville, Kansas, and Wynnewood, Oklahoma. So long as those facilities are operating, the company has a constant need to replenish the 6.4 million barrels of capacity in its storage tanks.

As a frequent buyer of oil, CVR offered Icahn a way to capitalize on the dislocation that has roiled so many others in crude markets. He had the company set up an account so it could use the futures market to buy supplies at a rock-bottom cost.

“When oil started sinking like that, I called then up and said, ‘Hey, we’ve got some storage space. Everyone’s going crazy for storage space,’” Icahn said.

Icahn, 84, made his reputation as a corporate raider in the 1980s, infamously buying airline TWA and selling off its assets in a prelude to bankruptcy. Since then, he’s restyled himself as a shareholder activist. His personal fortune, which reached $21.7 billion in February, has since fallen to about $17 billion, according to data compiled by Bloomberg.