We show that production networks amplify the effects of a firm’s financial constraints, generating substantive contagion effects on its partners’ investment. We quantify these effects via a network multiplier whereby a one-dollar drop in the constrained firm’s investment reduces total supply-chain investment by an additional dollar. To facilitate identification, we employ multiple financial-constraint measures, a Network Regression Discontinuity Design that accounts for covenant-violation spillovers, and an instrumented network of long-term partners. Consistent with production-driven spillovers, firms producing specific inputs generate larger investment spillovers and receive more trade credit. Overall, our results suggest that production networks aggregate firm-level financial frictions.