First, some credentials: I am a licensed and registered commodities broker (Series 3 & series 30), and deal with speculative markets on a daily basis at the investment brokerage I work for.

Speculation does affect prices. Speculators create new highs, and new lows. However, speculation by itself is not able to maintain recent highs (lows) without there being a fundamental reason - supply/demand - backing such prices.

While speculation may have caused oil prices to reach its new highs, without a fundamental backing these highs can only be maintained by speculators for hours, a day or two tops. The simple fact that global supply of oil is 85 million barrels/day while demand is 87 million barrels/day is the fundamental fact for oil prices to maintain their highs.

Congress is after the CFTC (Commodities Futures Trade Commission) to do something about these speculators. This has happened in the past, and in the past Congress got its way. Case in point: in 1958 Congress banned futures trading (speculation) on onions - this law still stands today. Onion farmers blamed "moneyed interests" - speculators - for major price movements, and lobbied Congress to ban trading on onions. As a result, onion prices are extremely volatile, swinging up and down 400% over 6 months in 2006.

A 1963 study by a Stanford economist, analyzing prices before and after the ban, showed that the speculators actually helped stabilize onion prices.

Moreover, it is important to note that contracts of buyers expecting the prices to go up must equal the value of contracts for sellers expecting the price to go down. Speculation is a means producers of goods can help protect themselves against future price changes. Speculative investments are not responsible, neither partly nor in whole, for our $4/gallon gas.