[Editor's note: This story was updated at 3:43 p.m. CT April 20.]

U.S. crude oil futures turned negative on April 20 for the first time in history, ending the day at a stunning minus $37.63/bbl as traders sold heavily because of rapidly filling storage space at the key Cushing, Okla., delivery point.

Brent crude, the international benchmark, also slumped, but that contract was nowhere near as weak because more storage is available worldwide.

The May U.S. WTI contract fell $55.90, or 306%, to settle at a discount of $37.63/bbl after touching an all-time low of -$40.32/bbl. Brent was down $2.51, or 9%, to settle at $25.57/bbl.

The June WTI contract traded more actively and settled at a much higher level of $20.43/bbl. The spread between May and June at one point widened to $60.76, the widest in history for the two nearest monthly contracts.

Physical demand for crude has dried up, creating a global supply glut as billions of people stay home to slow the spread of the novel coronavirus.

Investors bailed out of the May contract ahead of expiry later on Monday because of lack of demand for the actual oil. When a futures contract expires, traders must decide whether to take delivery of the oil or roll their positions into another futures contract for a later month.

Usually this process is relatively uncomplicated, but this time, there are very few counterparties that will buy from investors and take delivery of the oil. Storage is filling quickly at Cushing in Oklahoma, which is where the crude is delivered. "There is no bid for May WTI as there is no buyer and we have yet to see a significant reduction is supply at Cushing to offset it," said Scott Shelton, energy specialist at United ICAP.

Refiners are processing much less crude than normal, so hundreds of millions of barrels have gushed into storage facilities worldwide. Traders have hired vessels just to anchor them and fill them with the excess oil. A record 160 million barrels is sitting in tankers around the world.

Refinitive dismissed supply and demand as the culprit for the wild trading. Supply is clearly not the issue in the U.S. and while demand destruction might be blamed by some, the total collapse pointed to a demand disappearance, which is also not the case.

“This move happened too fast and went too far to rely on simple fundamentals,” said Carl Larry, performance director at Refinitive, in a statement released by the company.

Larry suspects that a large company engaged in a major selloff may have been the root cause.

“For those of us that have had the pleasure of working in a financial institution when customers are forced to liquidate, there is no price that is too low to sell,” he said. “Liquidation can be parsed out over a period of the day, but as more market participants become aware of position that needs to be liquidated, the bids (buyers) start to step away.”

With expiration a day away, Larry said, a more balanced trade would have been to sell today and tomorrow, but it seemed that haste on April 20 was dictated.

U.S. Crude stockpiles at Cushing rose 9% in the week to April 17, totaling around 61 million barrels, market analysts said, citing an April 20 report from Genscape.

"The storage is too full for speculators to buy this contract and the refiners are running at low levels because we haven't lifted stay-at-home orders in most states," said Phil Flynn, an analyst at Price Futures Group in Chicago. "There's not a lot of hope that things are going to change in 24 hours."

Many investors may have been misled by what appeared to be a very low oil price and did not consider the monthly expiry of futures contracts, Commerzbank analyst Carsten Fritsch said.

Prices have been pressured for weeks with the coronavirus outbreak hammering demand while Saudi Arabia and Russia fought a price war and pumped more. The two sides agreed more than a week ago to cut supply by 9.7 million bbl/d, but that will not quickly reduce the global glut.

Brent oil prices have collapsed around 60% since the start of the year, while U.S. crude futures have fallen around 95%, to levels well below break-even costs necessary for many shale drillers. This has led to drilling halts and drastic spending cuts.

More Data Sparks Global Economic Concerns

Weak global economic data also put pressure on prices. The German economy is in severe recession and recovery is unlikely to be quick as coronavirus-related restrictions could stay in place for an extended period, the Bundesbank said April 20.

Meanwhile, Japanese exports declined the most in nearly four years in March as U.S.-bound shipments, including cars, fell at their fastest rate since 2011.

The mood in other markets was also cautious as the first-quarter earnings season gets underway. Analysts expect STOXX 600 companies to post a 22% plunge in earnings, which would represent the steepest decline since the 2008 global financial meltdown, IBES data from Refinitiv showed.

Halliburton Co., which generates most of its oil business in North America, joined its larger rival Schlumberger Ltd. in taking impairment hits in the first quarter and issued a bleak outlook for North America.

Canada, the world's fourth-largest oil producer, has begun to rein in production, but analysts say the biggest cuts lie ahead.

The Russian energy ministry has told domestic oil producers to reduce oil output by around 20% from their average February levels, two industry sources told Reuters, which would bring Moscow in line with its commitment under a global deal.