The price at which you agree to buy the underlying security via the option is called the "strike price," and the fee you pay for buying that option contract is called the "premium." When determining the strike price, you are betting that the asset (typically a stock) will go up or down in price. The price you are paying for that bet is the premium, which is a percentage of the value of that asset.
Time Value: All options contracts have an expiration date, after which they become worthless. The more time that an option has before its expiration date, the more time there is available for the option to come into profit, so its premium will have additional time value. The less time that an option has until its expiration date, the less time there is available for the option to come into profit, so its premium will have either lower additional time value or no additional time value.
Volatility: If an options market is highly volatile (i.e. if its daily price range is large), the premium will be higher, because the option has the potential to make more profit for the buyer. Conversely, if an options market is not volatile (i.e. if its daily price range is small), the premium will be lower. An options market's volatility is calculated using its long-term price range, its recent price range, and its expected price range before its expiration date, using various volatility pricing models.
For example, if you believe the share price of a company currently trading for $100 is going to rise to $120 by some future date, you’d buy a call option with a strike price less than $120 (ideally a strike price no higher than $120 minus the cost of the option, so that the option remains profitable at $120). If the stock does indeed rise above the strike price, your option is in the money.
Strike Price: This is the price at which you could buy or sell the underlying futures contract. The strike price is the insurance price. Think of it this way: The difference between a current market price and the strike price is similar to the deductible in other forms of insurance. As an example, a December $3.50 corn call allows you to buy a December futures contract at $3.50 anytime before the option expires. Most traders do not convert options to futures positions; they close the option position before expiration.
Unlike other investments where the risks may have no boundaries, options trading offers a defined risk to buyers. An option buyer absolutely cannot lose more than the price of the option, the premium. Because the right to buy or sell the underlying security at a specific price expires on a given date, the option will expire worthless if the conditions for profitable exercise or sale of the option contract are not met by the expiration date. An uncovered option seller (sometimes referred to as the uncovered writer of an option), on the other hand, may face unlimited risk.
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.