Extremely short & simplified version, because this is complicated stuff: Goldman, among other places, got an exemption to laws limiting how many futures speculators could own. This law was meant to prevent people from buying up tons of futures in order to manipulate the price. With that exemption gone, people who otherwise had little to no interest in the relevant commodity markets would buy tons of them and hang on to them.
The supply actually went up. But because people would repeatedly say things like "give me $N worth of oil," eventually others got wise and started selling oil for $N a barrel.
I've probably skipped important details and garbled something, but that seems like an OK thumbnail sketch.
Extremely short & simplified version, because this is complicated stuff: Goldman, among other places, got an exemption to laws limiting how many futures speculators could own. This law was meant to prevent people from buying up tons of futures in order to manipulate the price. With that exemption gone, people who otherwise had little to no interest in the relevant commodity markets would buy tons of them and hang on to them.
The supply actually went up. But because people would repeatedly say things like "give me $N worth of oil," eventually others got wise and started selling oil for $N a barrel.
I've probably skipped important details and garbled something, but that seems like an OK thumbnail sketch.