The Chicago Mercantile Exchange (CME) is home to the spot cheddar cheese market, which impacts the prices of virtually all cheese traded in the United States, producer milk prices, and milk futures contracts. The spot cheese market, formerly the National Cheese Exchange (NCE) in Wisconsin, has been and continues to be the subject of concerns about price manipulation. The author was asked to examine (1) the market’s structure and ongoing concerns about price manipulation; (2) market oversight and efforts to address potential manipulation; and (3) how the market impacts federal milk pricing. In response, the author compared the markets at NCE and CME, analysed trading data, collected information about the Commodity Futures Trading Commission’s (CFTC) oversight, and met with industry participants, academics, and agency officials.