Capital gain is an economic concept defined as the profit earned on the sale of an asset which has increased in value over the holding period. An asset may include tangible property, a car, a business, or intangible property such as shares.

A capital gain is only possible when the selling price of the asset is greater than the original purchase price. In the event that the purchase price exceeds the sale price, a capital loss occurs. Capital gains are often subject to taxation, of which rates and exemptions may differ between countries. The history of capital gain originates at the birth of the modern economic system and its evolution has been described as complex and multidimensional by a variety of economic thinkers. The concept of capital gain may be considered comparable with other key economic concepts such as profit and rate of return, however its distinguishing feature is that individuals, not just businesses, can accrue capital gains through everyday acquisition and disposal of assets.