The sure was a good economic reason: the hurricane forecast. The people who were trading the futures saw that forecast and ran up the price in anticipation of a supply shortage. In their defense, if the forecast had been accurate they would have made gobs of money selling those $75 contacts at $100 a pop.
I really need to get in on the oil futures market. Those people are just bad decision-makers. They're wrong so often, it's scary.
And it's the oil futures market that really drives the conspiracy theories with regard to gas prices. If gas prices rose and fell due to actual measurable market forces, people wouldn't care, but that's not the way it goes. The oil futures market has that "man behind the curtain" feel to it.
It may be the way this incredibly conservative market functions, but it obscures its motivations and acts like an oligopoly. An oligopoly doesn't really want to make money, it just wants to hold its relative market share and is afraid to lose it.