Haha,another fight is coming.......

说的通俗一点，如果期权到期日还是比较长的话，那么在这样一段时间内期权在到期的时候价格运动到对持有人有利的位置的可能性就越大，因为这一段时间内的波动率是单位时间的波动率乘以时间的开平方。

这个理解是比较粗疏的，如果想好好的理解的话，看看John Hull的书好了。他有一本入门教材，可以看看。

i just recommand a classic book i know. You bet. Obviously, it is too hard for me to read through it. Maybe this book can be used only for reference to the beginners like me. I do not want to offend you here. Just discuss something we are interested. Do not be so sarcastic. If you know, you can also raise your answer. expecting your answer. :}
Hope someone can give us the correct and precise definition of time value of a option.

The answer is indeed in Hull' book. Mine is the 5th edition.

The time value of an option is the part of the option's value that derives the possibility of future favorable movements in the stock price. (pp 154)

Time value is the value of an option arising from the time left to maturiy (equals an option's price minus its intrinsic value). (pp 713)

At any rate, it's obviously not something like "the present value of option price".

[此贴子已经被作者于2007-2-25 11:57:38编辑过]

期权的时间价值（time value，也称为外在价值extrinsic value），是指期权购买者为购买期权而实际付出的期权费超过期权的内在价值那部分价值。购买者之所以乐于支付这部分费用，是因为他希望随着时间的推移和市场价格的变动，该期权的内在价值会得以增加。

期权的时间价值不易直接计算，一般是根据实际的期权价格减去该期权的内在价值而求得的。例如，一笔看涨期权的期权价格为9，执行价格为78，当时的标的资产市场价格为75，那么，该笔期权的内在价值为3，即78—75，而时间价值为6，即9—3.

[此贴子已经被作者于2007-2-26 10:13:27编辑过]

最近在研究currency， exchange rate...
同理STOCK OPTION
Currency Option
The time value of an option exists because the price of the underlying currency, the spot rate, can potentially move further and further into the money between the present time and the option's expiration date.

看涨期权价格为9，执行价格为78，当时的标的资产市场价格是75，内在价值应该为0才对吧。。
请教各位指点一下！！

可以这样理解：“期权的时间价值 == 价格P（在期权有效期内）达到平值的几率”在货币上的体现。

我也不明白。能再讲得详细点吗？

虚值期权：期货价格低于行权价格的看涨期权以及期货价格高于行权价格的看跌期权。虚值期权没有内涵价值，其权利金全部是时间价值