An option contract that may be exercised at any time between the date of purchase and the expiration date.
American Style Option, or American Option, is one of two options exercise styles in options trading. The other being the European Style Option. The main difference between American Style Options and European Style Options is the fact that American Style Options allow the holder to exercise the option at anytime prior to expiration while the former allows exercise only upon expiration. In fact, most exchanged traded options are American style options.
So, what is the benefits of being able to exercise an option prior to expiration? How are American Style Options priced? We shall cover these and more in this tutorial.
The two main options exercise styles are American Style exercise and European Style exercise. These names has nothing to do with where the options are traded. In fact, most exchanged traded options all over the world are American Style Options. American Style exercise allows an option to be exercised prior to expiration while European style exercise allows exercise only during expiration. This may look like a small difference but has led to differences in pricing methods and opens up new options trading strategies. So, what is the benefit of being able to exercise an option early prior to expiration?
When an option is exercised, all existing extrinsic value remaining in the option evaporates.
Early Exercise Example
Assuming AAPL is trading at $200 and you bought 1 contract of its call option with the strike price of $190 currently trading at $15.00. This call option has an intrinsic value of $10 and an extrinsic value of $5.00 with a total value of $1500. |
American Style Exercise Example
Assuming XYZ stock is trading at $50 and you own 1 contract of its call options at a strike price of $40 currently trading at $10.10. XYZ stock is expected to pay a dividend of about $0.50 per share or more according to its past dividend trends. In this case, it makes sense to exercise these call options early in order to receive the $0.50 and sacrifice the extrinsic value of $0.20 for an additional profit of $0.30. |
American Style Options are generally more expensive than European Style options due to this added benefit of being able to exercise the options early. However, you might notice that the Black-Scholes Model is widely used for pricing of American Style Options but the actual traded prices are usually higher than the theoretical values generated by the model. This is because the Black-Scholes options pricing model was designed with European Style Options in mind, not American Style Options. So far, there is no generally accepted method (true during time of writing at 2010) of pricing American Style Options even though many methods using regression, least squares, monte carlo or binomial has been proposed. So far, market forces of demand through implied volatility seems to be the major determinant of the extrinsic value of an American Style Option.
All equities options traded in the US market are American Style Options and are physically settled options. Basically, only cash settled options are European style options. You can check if an index option is American Style or European style by going to OIC's Product Specification Page.
Javascript Tree Menu |