From the Document: "On April 20, 2020, the futures contract price for the immediate month (May) of West Texas Intermediate (WTI), the U.S. benchmark crude, went negative (see Figure 1). The May futures contract price fell $55.90 during the day, to close at negative $37.62 per barrel. The futures price is a contract, usually monthly, for delivery of a certain amount of crude oil, on a specified date in the future, and at a particular location (Cushing, OK for WTI). WTI crude oil futures contracts are traded on the New York Mercantile Exchange (NYMEX). According to data from the U.S. Energy Information Administration (EIA), this is the first time in history that WTI prices became negative. However, other commodity prices, including natural gas and propane, have previously traded negatively."
CRS Insight, IN11354
Congressional Research Service: https://crsreports.congress.gov/