We develop a model of competitive financial markets in which investors hold opposing political preferences and firms choose political stances that generate non-pecuniary payoffs. In equilibrium, firms cater to the investor group with the greatest impact on their stock price, leading to endogenous corporate polarization and distorted risk sharing. Partisan firms generally have lower expected stock returns than politically neutral firms, and the minimum difference increases with financial costs of partisanship. Valuemaximizing political stances coincide with the utilitarian first best when cash flows are uncorrelated; with correlated cash flows, market incompleteness generically leads value maximization to diverge from welfare maximization.