From Longman Dictionary of Contemporary Englishmarketmakermar‧ket‧mak‧er /ˈmɑːkətˌmeɪkə $ ˈmɑːrkətˌmeɪkər/ noun [countable] British English technical BFSan organization such as a bank or a broker that keeps a supply of stocks and shares available for people who want to buy themFrom Longman Business Dictionarymarketmakermar‧ket‧mak‧er /ˈmɑːkətˌmeɪkəˈmɑːrkətˌmeɪkər/ (also market-maker) noun [countable]FINANCE a financial institution that always has supplies of shares available for buyersthe continued shortage of stock in the hands of marketmakersEach Big Board stock is entrusted to a single marketmaker, who constantly matches buy and sell orders.