Increasing Inventory Value in GL account

Hi,

Can some body throw light on this please?

Increasing Inventory value in GL account, without any transaction. For example one of our material 59.90.85.8921, stock qty 5 and on december 10th material value is 5464.56 and december 17th the material value 16485.56.For this material we did not do any transaction during this time.But we we donot know how this value of material is increased as 16485.56.

With Regards,

Jaheer