I show how financial intermediaries affect rental housing quality and affordability by supplying real estate investors with financing for quality improvement projects (i.e., renovations). First, I document a historic surge in improvement activity since the Great Recession. Then, using exogenous variation generated by a 2015 change in regulatory capital requirements, I find that a reallocation of bank credit toward improvement projects accounts for 24% of quality improvements since 2015. The shock increases the supply of high-quality apartments and lowers their rent. However, it raises the average apartment’s rent and accounts for 32% of historically high rent growth over 2015–16.

We show how securitization affects the size of the nonbank lending sector through a novel price-based channel. We identify the channel using a regulatory spillover shock to the cross-section of mortgage-backed security prices: the U.S. liquidity coverage ratio. The shock increases secondary market prices for FHA-insured loans by granting them favorable regulatory status once securitized. Higher prices lower nonbanks’ funding costs, prompting them to loosen lending standards and originate more FHA-insured loans. This channel accounts for 22% of nonbanks’ growth in overall mortgage market share over 2013–2015. While the shock creates risks for financial stability, homeownership also increases.