I develop a dynamic structural model in which a firm makes rational decisions to buy or sell assets in the presence of productivity shocks. By identifying equilibrium asset prices, the model also examines the aggregate asset sales activity over the business cycle. It shows that changes in productivity, rather than productivity levels, affect decisions: Firms with rising productivity buy assets and firms with falling productivity downsize (“rising buys falling”). As such, industries in which firms have less persistent and more volatile productivity experience greater asset reallocation. Using plant‐level data from Longitudinal Research Database (LRD), I find strong support for the model's predictions.

We document that public firms participate more than private firms as buyers and sellers of assets in merger waves and their participation is affected more by credit spreads and aggregate market valuation. Public firm acquisitions realize higher gains in productivity, particularly for on‐the‐wave acquisitions and when the acquirer's stock is liquid and highly valued. Our results are not driven solely by public firms' better access to capital. Using productivity data from early in the firm's life, we find that better private firms subsequently select to become public. Initial size and productivity predict asset purchases and sales 10 and more years later.