What is short selling?

Short selling means selling securities you do not own or have borrowed; it is a trade in which you sell when you expect the price to fall and later buy them back more cheaply to return them, profiting from the difference.

It has the advantage of improving the efficiency of price formation and liquidity, but its drawbacks include the risk of settlement failure and the potential for abuse as a means of market manipulation. If the share price rises contrary to expectations, you incur a loss.