A hedge is a position established in one market in an attempt to offset exposure to price changes or fluctuations in some opposite position with the goal of minimizing one's exposure to unwanted risk. There are many specific financial vehicles to accomplish this including insurance policies, forward contracts, swaps, options, many types of over-the-counter and derivative products, and perhaps most popularly, futures contracts. Public futures markets were established in the 19th century to allow transparent, standardized, and efficient hedging of agricultural commodity prices; they have since expanded to include futures contracts for hedging the values of energy, precious metals, foreign currency, and interest rate fluctuations.