The term "market loss" refers to the financial loss that occurs when the price of a security moves in the opposite direction of a trader's position in a trade. This is a common risk in the world of finance and can have significant impact on a trader's portfolio. It is important for investors to understand the concept of market loss and how to mitigate its effects through proper risk management strategies. Remember, staying informed and being prepared is key in navigating the ups and downs of the market.