A realized gain occurs when the sale price of an asset is higher than its carrying amount. This gain is only considered to be realized when the asset is removed from the entity's accounting records. Thus, a gain is only realized when the associated asset has been sold, donated, or scrapped. For example, an investor pays $1,000 for several shares of stock. Two years later, he sells the shares for $1,200. His realized gain is the $200 difference between the purchase price and the sale price of the stock. Until the investor sells the shares, any gain is classified as an unrealized gain. Unrealized gains are generally not taxed.
A realized gain is reported as taxable income. An entity may choose to delay selling an asset if it knows there will be a significant associated tax burden. Alternatively, it can sell other assets for which there will be realized losses, so that the losses offset the realized gain, resulting in a reduced tax or no tax at all.