This paper examines the implications of segmented assets markets for the real and nominal effects of monetary policy. I develop a model, in which varieties of consumption bundles are purchased sequentially. Newly injected money thus disseminates slowly through the economy via second-round effects and induces a non-degenerate, long-lasting heterogeneity in wealth. As a result, the effective elasticity of substitution differs across households, affecting optimal markups chosen by producers. In line with empirical evidence, the model predicts a short-term inflation-output trade-off, a liquidity effect, countercyclical markups, and procyclical profits and wages after monetary shocks.