Oil speculators are trading in oil futures contracts, not oil. Those futures are contracts to buy at a given price, and the agreed prices of those futures change with every transaction, usually up. And there's currently no limit on how many times futures contracts can be traded, and little requirement to report those trades.
Prices spike when Iran fires off missiles, when Nigerian oil workers threaten to strike, or when Israel conducts military exercises. That's not an actual change in the supply/demand curve, it's purely based on fear and speculation. If someone could control those fears, and they owned a lot of oil or oil futures, they could make a ton of money, your money.
If you Google oil prices, you'll see many articles stating that the latest jump to new record prices was due in part to a comment on oil prices by a Morgan Stanley analyst. Why is that significant? It's because Morgan Stanley is the worlds largest trader of oil futures and oil derivatives. They actually buy oil, as well as futures. They own some of the largest tankers in the world, holding 1 million barrels apiece. They don't produce, process, or store oil, it's all speculation. Well, they do store oil when they park their tankers waiting for the next well-timed spike. So if they can take another billion dollars out of the world's wallets by making a pessimistic comment about oil prices, why not? If oil prices fall, they could lose millions. Morgan Stanley shares were downgraded recently when this talk of regulating oil speculators started. Why? Because oil prices have to keep rising for companies like Morgan Stanley to keep profitting. If regulation happens, they may not be able to manipulate the market any more. This indicates that investment houses expect regulation to cause oil prices to fall, hurting Morgan Stanley.
I have very little experience or knowledge in this stuff, but I've been digging a little, out of curiosity.
Morgan Stanley May Run Larger Tankers for Oil Trades