We study the extent of interest rate risk sharing across the financial system using granular positions and transactions data in interest rate swaps. We show that pension and insurance (PF\&I) sector emerges as a natural counterparty to banks and corporations: overall, and in response to decline in rates, PF\&I buy duration, whereas banks and corporations sell duration. This cross-sector netting reduces the aggregate demand that is supplied by dealers. However, two factors impede cross-sector netting and add to substantial dealer imbalances across maturities: (i) PF\&I, bank and corporations' demand is segmented across maturities, and (ii) hedge funds trade large volumes with time-varying exposure. We test the implications of demand imbalances on asset prices by calibrating a preferred-habitat investors model with risk-averse arbitrageurs, who face both funding cost shocks and demand side fluctuations. We find that demand imbalances play a bigger role than arbitrageurs’ funding cost in determining the equilibrium swap spreads at all maturities. In counterfactual analyses, we demonstrate how demand shocks, e.g., regulation leading banks to hedge more, affect the hedging behavior of PF\&I. Our paper provides a quantity-based explanation for empirically observed asset prices in the interest rate derivatives market.