seventeenth century Japan. Futures contract Futures contracts are standardized forward contracts that are transacted through an exchange. In futures contracts the buyer and the seller stipulate product, grade, quantity and location and leaving price as the only variable. Agricultural futures contracts are the oldest, in use in the United States for more than 170 years. Modern futures agreements, began in Chicago in the 1840s, with the appearance of grain elevators. Chicago, centrally located, emerged as the hub between Midwestern farmers and east coast consumer population centers. Swaps A swap is a derivative in which counterparties exchange the cash flows of one party's financial instrument for those of the other party's financial instrument. They were introduced in the 1970s. Exchange-traded commodities (ETCs) Exchange-traded commodity is a term used for commodity exchange-traded funds (which are funds) or commodity exchange-traded notes (which are notes). These track the performance of an underlying commodity index including total return indices based on a single commodity. They are similar to ETFs and traded and settled exactly like stock funds. ETCs have market maker support with guaranteed liquidity, enabling investors to easily invest in commodities. They were introduced in 2003. At first, only professional institutional investors had access, but online exchanges opened some ETC markets to almost anyone. ETCs were introduced partly in response to the tight supply of commodities in 2000, combined with record low inventories and increasing demand from emerging markets such as China and India. Prior to the introduction of ETCs, by the 1990s ETFs pioneered by Barclays Global Investors (BGI) revolutionized the mutual funds industry. By the end of December 2009 BGI assets hit an all-time high of $1 trillion. Gold was the first commodity to be securitised through an Exchange Traded Fund (ETF) in the early 1990s, but it was not available for trade until 2003. The idea of a Gold ETF was first officially conceptualised by Benchmark Asset Management Company Private Ltd in India, when they filed a proposal with the Securities and Exchange Board of India in May 2002. The first gold exchange-traded fund was Gold Bullion Securities launched on the ASX in 2003, and the first silver exchange-traded fund was iShares Silver Trust launched on the NYSE in 2006. As of November 2010 a commodity ETF, namely SPDR Gold Shares, was the second-largest ETF by market capitalization. Generally, commodity ETFs are index funds tracking non-security indices. Because they do not