The Onion Futures Act (7 U.S.C Chapter 1 § 13-1]) is a United States law banning the trading of futures contracts on onions. It was passed on August 28, 1958, and remains in effect as of 2010[update].
This law is notable as the first and only ban on the trading of futures contracts of a specific commodity in United States history, and as a unique modern case with which to study the effects of the existence of an active futures market on commodity prices. In particular, proponents of futures markets often claim that they serve to stabilize otherwise volatile commodity supplies (and thus, prices) by providing a market-driven consensus mechanism for future price estimation. The conclusions drawn in subsequent studies of the effects of the Act upon price volatility have been mixed.