- UID
- 222320
- 帖子
- 448
- 主题
- 21
- 注册时间
- 2011-7-2
- 最后登录
- 2015-12-8
|
9#
发表于 2013-4-28 08:30
| 只看该作者
study2gether wrote:
For minimum and maximum values of options, why is European put options discounted at the risk free rate while American put options are not discounted.
This logic doesnt apply to European call/American call options.
like someone mentioned above, you have to discount european options because they can only be exercised at the expiry date ie at a future date. the maximum value of an european/american call is the spot/market price (because no one will be willing to pay more for the option than the market price of the underlying) of the underlying and that is already in PV terms (market price is price at time 0) ,therefore no need to discount. the maximum value of a put option is strike price (no one is willing to buy a put for more than the maximum they are hoping to sell the underlying for). however for an european put, you only settle at the expiry date in the future and thus the need to discount the strike price from expiry date to present value terms. for an american put, you can exercise now so the maximum will be the exercise price now, time 0 therefore no need to discount.
hope this makes sense! |
|