so, why is oil's price negative?
(note: I am a software developer who has an interest in finance. This is my understanding. I am not a professional.)
first, what does that even mean? so, the "price of oil" is the price of "WTI Crude", which is a specific kind of oil. There are multiple kinds of oil with multiple prices.
Why is it negative? to understand this, we also have to understand why WTI is the price of oil: that is, it's the kind of oil that underpins the New York Mercantile Exchange's oil futures contracts. The NYMEX is kind of like the stock market, but for commodities, aka stuff.