I build a model of delegated asset management with moral hazard and security lending. Lending markets transfer informational rents from short-sellers to funds. Investors optimally receive the proceeds as state-contingent dividends which correlate with shorting demand, providing a natural hedge....

We document low cross-sectional correlations between high-frequency market maker (MM) inventory positions, suggesting poor risk sharing. Using a unique data set on Canadian futures markets, a simple inventory cost estimate is 300% above the optimal benchmark. Our model explains how heterogeneity...