This paper examines the link between ownership concentration and corporate bond volatility. We show that more concentrated mutual fund ownership is associated with higher volatility of corporate bonds. This relation is stronger among more illiquid bonds, during periods of heightened bond market illiquidity, and among bonds held by corporate bond funds that invest in more illiquid bonds and experience higher or more correlated liquidity shocks. Using a sample of mutual fund mergers, we further show that increases in bond volatility are unlikely to be driven entirely by the endogenous ownership structure of corporate bonds. Our findings suggest that the concentrated ownership by corporate bond mutual funds provides another channel, apart from illiquidity, to help explain the excess volatility in corporate bonds.

Corporate bond spreads are affected by both credit risk and liquidity and it is difficult to disentangle the two factors empirically. In this paper we separate out the credit risk component by examining bonds that are issued by the same firm and that trade on the same day, allowing us to examine the effects of liquidity in a sample of bond pairs. We examine standard liquidity measures to determine how well they explain the differences in the two bonds’ yield spreads and find that the proxies do a poor job of measuring liquidity effects. Incorporating liquidity proxies related to other bonds issued by the firm and those for bonds of other firms can significantly improve the explanatory power. Still, a significant portion of the spread is left unexplained and it is largely driven by a common unknown factor. We conclude that good proxies for the liquidity component of corporate bond spreads remain elusive.