What is short-selling?
Short selling is the act of selling an asset that you do not currently own, in the hope that it will decrease in value and you can close the trade for a profit. It is also known as shorting. Short-sellers tend to use this strategy as a method of speculation or as a way of hedging downside risk.
Short selling strategies can be carried out via a broker, but it is a complicated method, which means that it can be difficult to find a broker willing to lend you the shares to sell. This is why derivative products such as CFDs and spread bets are becoming an increasingly popular method of short selling.