Short selling is the practice of borrowing securities to sell on the market with a view to buying the same securities back at a later date. Thus, a short seller hopes to profit from a fall in the price of the security.
Used carefully, short selling can be profitable, however, it does carry a degree of investment risk. In Australia, short selling is regulated by the Australian Securities and Investments Commission and monitored by the Australian Securities Exchange to ensure that it is not used for market manipulation.