The well-known equity home bias has two components: an extensive and intensive margin. Using data on direct stock holdings of U.S. households, we find that the decision to participate in foreign stock markets depends on investor wealth, with richer investors more likely to participate (the extensive margin). We document a new finding: as investor wealth increases, the portfolio share invested in foreign equities tends to decrease (the intensive margin). A noisy rational expectations equilibrium model with wealth heterogeneity, entry costs, and endogenously chosen information processing capacity can generate the new negative relationship and help understand the U.S. household equity home bias along both margins.