Up until recently, this was a fairly run-of-the-mill oil price crash – but then prices suddenly sunk below zero, with May futures for WTI oil closing at -$37.63 on April 20th. For the first time in history, producers were willing to pay traders to take oil off their hands. This oddity is partially a function of the particularities of futures contracts.
Source: https://www.visualcapitalist.com/subzero-oil-price-crash-covid-19/