Dramatic rises in the price of oil, gold and grains have sparked a debate over whether supply-demand fundamentals or a piling-on of new investors in the commodities markets have caused the increases. According to a U.S. market research firm, these recent sharp run-up in the price of oil and other commodities is mainly due to an influx of speculative investors. The U.S. market regulators recently indicated that market fundamentals were the main cause.

According to Greenwich Associates, a Connecticut-based firm that has been studying U.S. markets for 36 years, new research shows that more than a third of commodities investors have been active in these markets for less than three years. Pension funds, European banks and hedge funds are the three main sources helping to drive financial markets’ activity in commodities.

U.S. crude oil hit a new record peak near $130 a barrel Tuesday, almost double the level of a year ago. Prices of wheat, corn, soybeans, rice, gold and copper have also hit all-time peaks in U.S. trade this year.

The farming groups and food producers says that an inordinate rise in speculative trading by investment funds has added volatility to grains at least, and has undermined the role of futures markets to determine prices and help manage risk.