There has been tremendous growth in the study of the Roman economy since M. I. Finley penned his rather gloomy "Further Thoughts" on the topic in 1984. The sheer amount of material now available is both impressive and intimidating. Generally speaking, the New Institutional Economics approach, which views institutions as the primary determinants of economic performance because of their effect on transaction costs, has come to dominate Roman economic history. This is a positive development, but attempts to answer macroeconomic questions, such as the nature and extent of growth in the Roman economy, sometimes obscure the role of the individual economic actor: much has been published recently on trade and markets, not enough on traders and merchants .2 This chapter approaches the Roman economy from the perspective of the trader. I begin by asking who traders were, where, with whom, and under what conditions they worked, what they traded, as well as the environmental, social, and technological factors constraining their behavior. Then I turn to two narrower questions. First, to what extent did Roman traders compete with one another? Second, what can Roman discourse about "business ethics" tell us about the market context in which traders operated? Because substantial changes· took place in the late antique economy ,3 this chapter focuses on the late Republican and early Imperial periods. In addition to illustrating the world inhabited by the Roman trader, I hope to demonstrate that modern economic approaches do help us understand the Roman economy, in part because modern traders continue to grapple with many of the same challenges faced by their ancient colleagues.