Most studies of ancient trade, it is argued, have tended to isolate the subject too narrowly as habitual patterns in the movement of goods. New knowledge continues to be generated using that approach, partly as a result of recent technical advances in archaeology. Substantial further progress, however, will require an understanding of the more complex and multifaceted significance of trade that must be derived mainly from ethnographic and ethnohistoric sources. Trade frequently has been a vital component, for example, in adaptive social responses to risk and uncertainty. Its dynamic effects are suggested by the shifting boundary between trade and intergroup predation. The unstabilizing, generative aspects of trade are, therefore, among its most crucial features. Rather than reflecting broad and undifferentiated sociocultural orientations or patterns, they may stem in large part from the economic entrepreneurship and other goal-motivated behavior of self-conscious individuals and groups. Hence they point to the need for a less gradualist orientation, and correspondingly greater emphasis on exogenous sources of change, in the evolutionary study of early ranked and stratified societies. Examples are adduced in support of this position from the ancient Near East and from North America and Africa around the time of European contact.