Capital gain

positive difference between the buying and selling prices of a property (Economics)

In finance, a capital gain is profit that results from the sale or exchange of a capital asset over its purchase price. If the price of the capital asset has declined instead of appreciated, this is called a capital loss. Capital gains occur in both real assets, such as property, as well as financial assets, such as stocks or bonds.
See more at Wikipedia.org...

Noun
1. the amount by which the selling price of an asset exceeds the purchase price; the gain is realized when the asset is sold
(hypernym) financial gain

When a stock is sold for a profit, it's the difference between the net sales price of securities and their net cost, or original basis. If a stock is sold below cost, the difference is a capital loss.