Stock Price Fragility

Robin  Greenwood; David  Thesmar

Article | Journal of Financial Economics | December 2011

Stock Price Fragility

Abstract

We investigate the relationship between ownership structure of financial assets and non-fundamental risk. We define an asset to be fragile if it is susceptible to non-fundamental trading shocks. An asset can be fragile because of concentrated ownership or because its owners face correlated liquidity shocks, i.e., they must buy or sell at the same time. Two assets are co-fragile if their owners have correlated trading needs, even if the holdings of these owners do not directly overlap. We formalize this idea and apply it to the ownership of U.S. stocks between 1990 and 2007. Consistent with our predictions, fragility strongly predicts future price volatility, and co-fragility predicts cross-stock return comovement.

Keywords: Stocks; Price; Ownership; Risk and Uncertainty; Assets; System Shocks; Financial Liquidity; Forecasting and Prediction; Investment Return; Volatility; Relationships; United States;

Format: Print

SSRN Find at Harvard

Citation:

Greenwood, Robin, and David Thesmar. "Stock Price Fragility." Journal of Financial Economics 102, no. 3 (December 2011).

We develop a model in which risk-averse, specialized bond investors must be paid to absorb shocks to the supply and demand for long-term bonds in two currencies. Since long-term bonds and foreign exchange are both exposed to unexpected movements in short-term interest rates, our model naturally links the predictability of long-term bond returns to the predictability of foreign exchange returns. Specifically, a shift in the net supply of long-term bonds in one currency influences bond term premiums in both currencies as well as the foreign exchange rate between the two currencies. Our model matches several important empirical patterns, including the co-movement between exchange rates and bond term premiums as well as the finding that central banks' quantitative easing policies impact not only local-currency long-term yields, but also foreign exchange rates. We also show that this quantity-driven approach provides a unified account explaining both why foreign exchange tends to outperform when the foreign interest rates exceed domestic rates and why long-term bonds tend to outperform when the yield curve is steep.

Reflexivity is the idea that investors' biased beliefs affect market outcomes, and that market outcomes in turn affect investors' beliefs. We develop a behavioral model of the credit cycle featuring such a two-way feedback loop. In our model, investors form beliefs about firms' creditworthiness, in part by extrapolating past default rates. Investor beliefs influence firms' actual creditworthiness because firms that can refinance maturing debt on favorable terms are less likely to default in the short run—even if fundamentals do not justify investors' generosity. Our model is able to match many features of credit booms and busts, including the imperfect synchronization of credit cycles with the real economy, the negative relationship between past credit growth and the future return on risky bonds, and "calm before the storm" periods in which firm fundamentals have deteriorated but the credit market has not yet turned.

On the afternoon of Monday October 13, 2008, Hank Paulson Jr., the Secretary of the Treasury of the United States, walked into the large conference room across the hall from his office in the Treasury Department. Joining him were Federal Reserve Chairman Ben Bernanke, President of the Federal Reserve Bank of New York Timothy Geithner, Chair of the Federal Deposit Insurance Corporate Sheila Bair, and the Chief Executive Officers of nine of the largest banks in the United States. This distinguished group had been brought together by the most serious financial crisis since the Great Depression of the 1930s. Financial panic was pushing the U.S. and European financial systems to the brink of failure. Paulson hoped his meeting with the bank CEOs would be a turning point. U.S. financial markets were closed for Columbus Day, and Paulson was planning to announce the latest government actions to stabilize the financial system before markets reopened on Tuesday.

Faculty & Research

Stock Price Fragility

Abstract

Citation:

About the Author

More from the Author