a market where anyone can buy and sell 自由市场◆When the contract expired, the plant was forced to sell its electricity on the open market. 合同到期，这家工厂被迫在自由市场上售电。
used to refer to the situation when a country's central bank buys and sells government bonds, etc. in financial markets in order to control interest rates and the money supply (= the total amount of money that exists in the economy of a country at a particular time) 公开市场（指一国中央银行为了控制利率和货币供应量而在金融市场买卖政府债券等）