Evidence grows in support of the longstanding suspicion by many oil and gas operators that trading of financial instruments related to crude oil, oil products, and natural gas unduly influences prices of those commodities. In the shorthand of the day, speculation increases price volatility. In the politics of the day, speculators are demonic.Speculators—or noncommercial traders, who seek trading profits with no intention of taking possession of what they trade—are in fact essential to market fluidity. Among other things, they assume price risks unwanted by buyers and sellers of physical commodities.But a recent increase in speculative activity coincides with a decrease in regu...