This paper studies trade in endogenously evolving markets exhibiting few traders at any given point in time. Traders arrive in the market and bargain until they complete a trade. We find that, unlike large markets, small markets feature trade delay and price dispersion, even when sellers and buyers are homogeneous and matching frictions are small. We characterize transaction prices as a function of the endogenous evolution of the market composition and economic conditions, providing several novel comparative statics results. Our analysis highlights the need to incorporate sub-market structures into the theoretical study of job, real estate, and rental markets, where trade opportunities are typically constrained by both the geographical location and individual characteristics of each trader.