Offer your thoughts or opinion on the input financial query or topic using your financial background.

Why do shareholders participate in shorting stocks?
Why would a shareholder lend the investor the shares? Some brokers like IB will pay you to lend your shares: http://ibkb.interactivebrokers.com/node/1838 If you buy shares on margin, you don't have much of a choice. Your broker is allowed to lend your shares to short-sellers.