Corporate bond prices are slow to respond to default risk and interest rate shocks, as proxied by firm-level stock returns and Treasury returns, respectively. Furthermore, the underreaction is risk-specific: bonds with better credit quality underreact more to default risk, while those with worse quality underreact more to interest rates. The underreactions imply substantial out-of-sample return predictability, and investors appear to be leaving too much money on the table. The results are consistent with behavioral inattention models in which investors endogenously allocate more attention to payoff-relevant (or salient) risks, and they are not explained by traditional trading friction mechanisms.

Classical asset pricing models predict that optimizing investors exhibit extremely high demand elasticities, while empirical estimates are significantly lower—by three orders of magnitude. To reconcile this disparity, we introduce a novel decomposition of investor demand elasticity into two key components: “price pass-through”, which captures how price movements forecast returns, and “unspanned returns”, reflecting a stock’s lack of perfect substitutes. In a factor model framework, we show that unspanned returns become significant when models include “weak factors”. Classical models overestimate demand elasticity by assuming both very low unspanned returns and high price pass-throughs, assumptions that are inconsistent with empirical evidence.