This is the simplified version of what the “-$36.73 a barrel oil” means if anyone is not into futures contracts.
A futures contract is a contract to buy something in the future at a pre-agreed price.
When you buy most commodity contracts e.g. for oil or soybean or orange juice, you actually buy the “physical” product at a future delivery date.
If you don’t close out your oil or soybean contract, you get a call from the exchange telling you that your soybeans are waiting for you in Kansas City and what would you like to do with them? Imagine that problem.
Same with oil. Tankers will show up in Houston with millions of gallons of oil and somebody needs to take the delivery. Nobody can because all the storage facilities are already full. So people that bought these future contracts (in the hope they would be able to sell them at profit) are literally paying you almost $37 a barrel for you to take possession of oil.
Crazy times.