The standardisation usually involves specifying:
Because they vary in price as a direct function of these variables only, a futures contract is an example of a parametric contract[?], and is easily combined or traded as part of more complex financial derivatives[?] deals.
Margin Although the value of a contract at time of trading should be zero, its price constantly fluctuates. This renders the owner liable to adverse changes in value, and creates a credit risk[?] to the exchange. To minimise this risk, the exchange demands that contract owners post a form of collateral[?], known as margin. The amount of margin changes each day, involving movements of cash handled by the exchange's clearing house[?].
Margin requirements are waived or reduced in some cases for hedgers who have physical ownership of the covered commodity or offsetting contracts for its purchase or sale.
Initial margin[?] is paid by both buyer and seller. It represents the loss on that contract, as determined by historical price changes, that is not likely to be exceeded on a usual day's trading.
Because a series of adverse price changes may exhaust the initial margin, a further margin, usually called variation margin[?], is called by the exchange. This is calculated by the futures contract, i.e. agreeing a price at the end of each day, called the "settlement" or mark-to-market[?] price of the contract.
Margin-equity ratio is a term used by speculators[?], repesenting the amount of their trading capital that is being held as margin at any particular time. Traders would rarely (and unadvisedly) hold 100% of their capital as marign. The probability of losing their entire capital at some point would be high. By contrast, if margin-equity so low as to make the trader's capital equal to the value of the futures contract itself, not profit from the inherent leverage implicit in futures trading. A conservative trader might margin-equity at 15%, a more aggressive trader at 40%.
Delivery Delivery is the act of actually delivering (for sales) or accepting delivery (for purchases) of the underlying contract after trading has ceased. There are two main methods of delivery:
Delivery normally occurs only on a minority of contracts. Others are cancelled out by purchasing a covering position, that is, buying a contract to cancel out an earlier sale (covering a short), or selling a contract to cover an earlier purchase (covering a long).
Pricing The price of a future is derived via arbitrage arguments: the forward price represents the expected future value of the underlying discounted at the risk free rate. Any deviation from the theoretical price will afford investors a riskless profit opportunity and will quickly be arbitraged away. Thus, for a simple, non-dividend paying asset, the value of the future/forward, F(t), will be found by discounting the present value S(t) at time t to maturity T by the rate of risk-free return r.
F(t) = S(t)*(1+r)^(T-t) or, with continuous compounding F(t) = S(t)e^r(T-t)
This relationship may be modified for storage costs, dividends, dividend yields, and convenience yields.
In a perfect market the relationship between futures and spot prices depends only on the above variables; in practice there are various market imperfections (transaction costs, differential borrowing and lending rates, restrictions on short selling) that prevent complete arbitrage. Thus, the futures price in fact varies within arbitrage boundaries around the theoretical price.
Futures contracts and exchanges There are many different kinds of futures contract, reflecting the many different kinds of tradeable assets which they are derivatives of. For information on futures markets in specific underlying commodity markets, follow the links.
Originally, futures were traded only on commodities, in a market dominated by Chicago. However, after their introduction in the 1970's, contracts on financial instruments became hugely successful and quickly overtook commodities futures in terms of trading volume and global accessibility to the markets. This led to the introduction of many new futures exchanges across the world, such as LIFFE[?], EUREX[?] and TIFFE[?].
Who trades futures? Futures traders are traditionally placed in one of two groups: hedgers[?], who have an interest in the underlying commodity and are seeking to hedge out the risk of price changes; and speculators[?], who seek to make a profit by predicting market moves and buying a commodity "on paper" for which they have no practical use.
Hedgers typically include producers and consumers of a commodity. For example, farmers often sell futures for the crops and livestock they produce to guarantee a certain price, making it easier for them to plan. Similarly, livestock producers often purchase futures to cover their feed costs, so that they can plan on a fixed cost for feed.
The presence of hedgers is often used as moral justification for the existence of the markets, which would otherwise appear to be a system of organized gambling.
Options on futures In many cases, options are traded on futures. A put is the option to sell a futures contract, and a call is the option to buy a futures contract; both specify a futures price (the option strike price) at which the trade occurs if the option is exercised. See the Black model, which is used for the pricing of these option contracts.