COLLAR

a derivative instruments investing term where an investor puts a "collar" around investment risk, usually by selling a put option (an option to purchase) and purchasing a call option (an option to sell) around an investment. Amgen and Oracle sold put warrants on their own common stock and then used the proceeds to purchase calls on the same stock. This process is called a "costless collar" and is used to express a bullish view of the stock by management.