What is the tax on profit from selling an investment or other asset called?

A tax on profit from selling an investment or other asset is called capital gains tax.

A capital gain generally arises when an asset is sold for more than its tax basis, often the purchase price adjusted under local rules. Assets that may produce gains include shares, bonds, land, buildings, and some valuable personal property. The taxable gain is usually the profit, not the full sale price.

Many tax systems distinguish between short-term and long-term gains. The United States, for example, generally treats assets held for more than one year differently from assets held for one year or less. Rates, exemptions, deductions, and treatment of losses vary substantially between countries.

Capital gains tax is not the same as a sales tax. A sales tax is charged on a transaction, commonly to the buyer, while capital gains tax concerns the seller’s profit. An unrealized gain—the increase in value before an asset is sold—is usually treated differently from a realized gain.