We develop a two-country model in which currency and bond markets are populated by different investor clienteles, and segmentation is partly overcome by arbitrageurs with limited capital. Risk premia in our model are time-varying, connected across markets, and consistent with the empirical violations of uncovered interest parity and expectations hypothesis. Through risk premia, large-scale bond purchases lower domestic and foreign bond yields and depreciate the currency, and short-rate cuts lower foreign yields, with smaller effects than bond purchases. Currency returns are disconnected from long-maturity bond returns, and yet the currency market is instrumental in transmitting bond demand shocks across countries. (JEL E43, E44, E52, F31, G12, G15)

Abstract We study how passive investing affects asset prices. Flows into passive funds disproportionately raise the stock prices of the economy’s largest firms, especially those large firms in high demand by noise traders. Because of this effect, the aggregate market can rise even when flows are entirely due to investors switching from active to passive funds. Intuitively, passive flows increase the idiosyncratic risk of large firms in high demand, which discourages investors from correcting the flows’ effects on prices. Consistent with our theory, prices and idiosyncratic volatilities of the largest S&P500 firms rise the most following flows into that index.