In looking at the role of speculation on oil prices, a Senate committee is looking at increasing margin requirements:

“I think there’s an orgy of speculation that we ought to be deciding to do something about,” said Sen. Byron Dorgan, D-North Dakota.

He and others raised the idea of changing the margin or amount investors must pay up front in order to engage in oil speculation. It would be a hugely significant change in financial markets. Dorgan said stock speculation requires a 50% margin, but commodities like oil demand a much lower threshold, just 5% or 7%.

If you look at the credit crunch generally, the real problem is excessive leverage. Margins should be raised to the 75% range, where they were for stocks before the Fed cut them around 1980, and they should be applied to all investments.