Buying to cover is different than simply buying a stock. When an investor wants to buy and hold a stock, they place a standard buy order. In contrast, a buy-to-cover order is designed to close out a short position. An investor buying to cover does not own the stock once the transaction is complete since the investor had borrowed shares that needed to be returned.
An investor who shorts a stock may enter a buy-to-cover limit order, which is structured to take advantage of any dips in the stock price by specifying a target maximum price at which the buy-to-cover order can be executed. If an investor shorts a stock when it trades for $50, then a buy-to-cover limit order with a $40 limit ensures that the investor receives a profit of $10 per share if the stock price ever dips below $40.
In contrast to an investor buying a stock, and can then profit by selling the stock at a higher price, an investor shorting a stock profits if the stock decreases in price. Investors who are buying to cover are locking profits or losses from the short sale of a stock.