The oil bubble: Set to burst?" That was the headline of an October 2004 article in National Review, which argued that oil prices, then $50 a barrel, would soon collapse. Ten months later, oil was selling for $70 a barrel. "It's a huge bubble," declared Steve Forbes, the publisher, who warned that the coming crash in oil prices would make the popping of the technology bubble "look like a picnic." All through oil's five-year price surge, which has taken it from $25 a barrel to last week's close above $125, there have been many voices declaring that it's all a bubble, unsupported by the fundamentals of supply and demand. So here are two questions: Are speculators mainly, or even largely, responsible for high oil prices? And if they aren't, why have so many commentators insisted, year after year, that there's an oil bubble? Now, speculators do sometimes push commodity prices far above the level justified by fundamentals. But when that happens, there are telltale signs that just aren't there in today's oil market. Imagine what would happen if the oil market were humming along, with supply and demand balanced at a price of $25 a barrel, and a bunch of speculators came in and drove the price up to $100. Even if this were purely a financial play on the part of the speculators, it would have major consequences in the material world. Faced with higher prices, drivers would cut back on their driving; homeowners would turn down their thermostats; owners of marginal oil wells would put them back into production. As a result, the initial balance between supply and demand would be broken, replaced with a situation in which supply exceeded demand. This excess supply would, in turn, drive prices back down again