In the over-the-counter market, the term “bid” refers to the highest price at which a market maker or broker is willing to pay in order to buy a security (e.g. currency, stock, index or commodity) at any given time. The bid price will almost always be lower than the “ask” price (= the lowest price a market maker or broker is willing to sell a security at any given time). Market makers and brokerage firms make money on the difference between the bid price and the ask price. This difference is called the “bid ask spread”.