This paper establishes three empirical results. We find positive autocorrelation in actual intra‐day stock returns, in intra‐day returns computed from quote midpoints, and in the arrival of buy and sell orders. We present a model of return generation that incorporates these features via lagged adjustment of the limit‐order price and positive dependence in bid and ask transactions. The return model is observationally equivalent to an ARMA process, which is consistent with the observed return behavior.