fair value through p/l

If the market price of the asset is representing the fair value of it, you can make profits or incur losses by buying and selling on that asset. Consequently, if market price if lower than its fair value, you can make profits by buying it and the sell it at fair value after the market price is reflecting its fair value.

2010-09-23 15:06:31 補充：
Yes you are right. If the assets are classified as 'held to maturity', they are not required to 'mark to market' to reflect their market values.