We show short selling in corporate bonds forecasts future bond returns. Short selling predicts bond returns where private information is more likely, in high-yield bonds, particularly after Lehman Brothers’ collapse of 2008. Short selling predicts returns following both high and low past bond returns. This, together with short selling increasing following past buying order imbalances, suggests short sellers trade against price pressures as well as trade on information. Short selling predicts bond returns both in the individual bonds that are shorted and in other bonds by the same issuer. Past stock returns and short selling in stocks predict bond returns but do not eliminate bond short selling predicting bond returns. Bond short selling does not predict the issuer’s stock returns. These results show bond short sellers contribute to efficient bond prices and that short sellers’ information flows from stocks to bonds but not from bonds to stocks.