In finance, short selling (also known as shorting or going short) is the practice of selling assets, usually securities, that have been borrowed from a third party (usually a broker) with the intention of buying identical assets back at a later date to return to the lender. The short seller hopes to profit from a decline in the price of the assets between the sale and the repurchase, as he will pay less to buy the assets than he received on selling them. Conversely, the short seller will incur a loss if the price of the assets rises. Other costs of shorting may include a fee for borrowing the assets and payment of any dividends paid on the borrowed assets. Shorting and going short also refer to entering into any derivative or other contract under which the investor profits from a fall in the value of an asset.

Going short can be contrasted with the more conventional practice of "going long", whereby an investor profits from any increase in the price of the asset.