Call writers and put writers (sellers), however, are obligated to buy or sell if the option expires in-the-money (more on that below). This means that a seller may be required to make good on a promise to buy or sell. It also implies that option sellers have exposure to more, and in some cases, unlimited, risks. This means writers can lose much more than the price of the options premium.
For example: Tomatoes are cheap in July and will be expensive in January, you can’t buy them in July and take delivery in January, since they will spoil before you can take advantage of January’s high prices. The July price will reflect tomato supply and demand in July. The forward price for January will reflect the market’s expectations of supply and demand in January. July tomatoes are effectively a different commodity from January tomatoes.
Fluctuations in option prices can be explained by intrinsic value and extrinsic value, which is also known as time value. An option's premium is the combination of its intrinsic value and time value. Intrinsic value is the in-the-money amount of an options contract, which, for a call option, is the amount above the strike price that the stock is trading. Time value represents the added value an investor has to pay for an option above the intrinsic value. This is the extrinsic value or time value. So, the price of the option in our example can be thought of as the following:
Traders that are willing to accept considerable amounts of risk with the prospects of limited reward, can write (or sell) options, collecting the premium and taking advantage of the well-known belief that more options than not expire worthless. The premium collected by a commodity option seller is seen as a liability until the option is either offset (by buying it back), or it expires. This is because as long as the option position is open (the trader is short the commodity option), there is substantial risk exposure. Should the futures price trade beyond the strike price of the option, the risk is similar to holding a commodity futures contract outright.
In Economics, a commodity is a marketable item produced to satisfy wants or needs. The commodity is generally Fungible (Fungibility is the property of a good or commodity whose individual units are capable of being substituted in place of one another). For example, since one ounce of pure gold is equivalent to any other ounce of pure gold, gold is fungible. Other fungible goods are Crude oil, steel, iron ore, currencies, precious metals, alloy and non-alloy metals.
However, options are not the same thing as stocks because they do not represent ownership in a company. And, although futures use contracts just like options do, options are considered lower risk due to the fact that you can withdraw (or walk away from) an options contract at any point. The price of the option (its premium) is thus a percentage of the underlying asset or security.