Since the introduction of its quantitative and qualitative easing program in 2013, the Bank of Japan has been increasing its holdings of Japanese equity through large-scale purchases of index-linked ETFs, to lower risk premiums. We exploit the cross-sectional heterogeneity of the supply shock to identify a positive and persistent impact on stock prices, consistent with a portfolio balance channel. The evidence suggests that long-run demand curves for stocks are downward sloping with unitary price elasticity. We show that the purchases of ETFs tracking the price-weighted Nikkei 225 generate pricing distortions relative to a value-weighted benchmark. Received April 13, 2018; editorial decision July 18, 2019 by Editor Thierry Foucault.