This paper considers the history of governance and speculation on US derivative markets from their emergence in the middle of the 19th century through their incursion into finance in the late 20th century. It explores the importance of derivatives’ extended ancestry in agricultural markets before analyzing their entanglement with financial markets, which came much later in the 1970s and 1980s. The paper is particularly concerned with the institutional inheritance of a set of legal–regulatory boundaries that prioritized price making and the speculative trading that was necessary to produce a consistent flow of prices. This governance system for derivatives is set in contrast with the governance of securities markets, which during the 1930s became subject to more strict government oversight, particularly with regard to speculative trading. The legal boundaries between these two markets began to deteriorate in the 1970s when the Chicago derivative exchanges applied the speculative logic of agricultural derivative markets to financial instruments. The implications of this are twofold. First the paper argues that market mechanisms and market regulation are analytically inseparable, and ought to be studied as such. Second, employing this approach, the paper argues that US financial derivative markets are originally ‘derivative’ not of New York and the finance sector, but of Chicago and the agricultural sector. </jats:p