A commodity market is a market that trades in the primary economic sector rather than manufactured products, such as cocoa, fruit and sugar. Hard commodities are mined, such as gold and oil. Futures contracts are the oldest way of investing in commodities. Futures are secured by physical assets. Commodity markets can include physical trading and derivatives trading using spot prices, forwards, futures, and options on futures. Farmers have used a simple form of derivative trading in the commodity market for centuries for price risk management.A financial derivative is a financial instrument whose value is derived from a commodity termed an underlier. Derivatives are either exchange-traded or over-the-counter (OTC). An increasing number of derivatives are traded via clearing houses some with central counterparty clearing, which provide clearing and settlement services on a futures exchange, as well as off-exchange in the OTC market.Derivatives such as futures contracts, Swaps (1970s-), Exchange-traded Commodities (ETC) (2003-), forward contracts have become the primary trading instruments in commodity markets. Futures are traded on regulated commodities exchanges. Over-the-counter (OTC) contracts are "privately negotiated bilateral contracts entered into between the contracting parties directly".Exchange-traded funds (ETFs) began to feature commodities in 2003. Gold ETFs are based on "electronic gold" that does not entail the ownership of physical bullion, with its added costs of insurance and storage in repositories such as the London bullion market. According to the World Gold Council, ETFs allow investors to be exposed to the gold market without the risk of price volatility associated with gold as a physical commodity.