(
FINANCE) the increase in wealth that goes to the owner of a financial
asset when it increases in value. If you buy a share of stock, and the share increases in value, then you have capital gains whether you have sold it or not.
If you sell the stock at the higher price, you have made money on the
transaction and have "realized capital gains." If you hang onto the asset in the hopes its value will increase even more, you have "unrealized capital gains."