We provide evidence that agents have slow‐moving beliefs about stock market volatility that lead to initial underreaction to volatility shocks followed by delayed overreaction. These dynamics are mirrored in the VIX and variance risk premiums, which reflect investor expectations about volatility, and are also supported in both surveys and firm‐level option prices. We embed these expectations into an asset pricing model and find that the model can account for a number of stylized facts about market returns and return volatility that are difficult to reconcile, including a weak or even negative risk‐return trade‐off.

We examine how the payment processing role of banks affects their lending activity. In our model, banks operate in separate zones, and issue claims to entrepreneurs who purchase some inputs outside their own zone. Settling bank claims across zones incurs a cost. In equilibrium, a liquidity externality arises when zones are sufficiently different in their outsourcing propensities—a bank may restrict its own lending because it needs to hold liquidity against claims issued by another bank. Our work highlights that the disparate motives for interbank borrowing (investing in productive projects and managing liquidity) can have different effects on efficiency.

Using proprietary financial data on millions of households, we show that likely‐Republicans increased the equity share and market beta of their portfolios following the 2016 presidential election, while likely‐Democrats rebalanced into safe assets. We provide evidence that this behavior was driven by investors interpreting public information based on different models of the world. We use detailed controls to rule out the main nonbelief‐based channels such as income hedging needs, preferences, and local economic exposures. These findings are driven by a small share of investors making big changes, and are stronger among investors who trade more ex ante.