Stocks can be borrowed from a stock broking platform like CMC Markets. For example, if a company is trading for $400 a share and you believe there is a short-selling opportunity, you can borrow 10 shares from your broker and sell them for a total of $4000. If the share price subsequently falls to $300 a share, you can close your short position and buy back the 10 shares for $3000, leaving you with a $1000 profit, excluding fees and interest.