Contract Months (Time): All options have an expiration date; they only are valid for a particular time. Options are wasting assets; they do not last forever. For example, a December corn call expires in late November. As assets with a limited time horizon, attention must be accorded to option positions. The longer the duration of an option, the more expensive it will be. The term portion of an option's premium is its time value.

In case of futures, a buyer of a contract is said to be “long position holder” and a seller is “Short position holder”. In the case of futures, to avoid the risk of defaulting contract involves both parties lodging a certain percentage margin of value of contract with a mutually trusted third party. Generally, in gold futures trading, margin varies between 2%-20% depending on the volatility of gold in spot market.
Trading in commodity futures contracts can be very risky for the inexperienced. The high degree of leverage used with commodity futures can amplify gains, but losses can be amplified as well. If a futures contract position is losing money, the broker can initiate a margin call, which is a demand for additional funds to shore up the account. Further, the broker will usually have to approve an account to trade on margins before they can enter into contracts.
When buying or selling options, the investor or trader has the right to exercise that option at any point up until the expiration date - so simply buying or selling an option doesn't mean you actually have to exercise it at the buy/sell point. Because of this system, options are considered derivative securities - which means their price is derived from something else (in this case, from the value of assets like the market, securities or other underlying instruments). For this reason, options are often considered less risky than stocks (if used correctly).