International Finance Review

Institutional investors have increasingly gained importance since the early 1990s. The assets under management in these funds have increased threefold since 1990 to reach more than US$45 trillion in 2005, including over US$20 trillion in equity (Ferreira & Matos, 2008). Further, the value of institutional investors' assets represents roughly 162.6% of the OECD gross domestic product in 2005 (Gonnard, Kim, & Ynesta, 2008). Given the magnitude of institutional investors' holdings relative to the world market capitalization, challenging questions on the economic role of these investors have been raised. One such question concerns their impact on the stability of stock markets. On the one hand, active strategies of buying and selling shares by these investors may contribute to moving stock prices away from their fundamental values. On the other hand, if all institutional investors react to the same information in a timely manner, they are in fact helping to increase market efficiency by speeding up the adjustment of prices to new fundamentals (for competing theories on the role of institutional investors, see, e.g., Lakonishok, Shleifer, & Vishny, 1992). This view of institutional investors as “efficiency drivers” generated considerable debate for many years (see, e.g., Ferreira & Laux, 2007; French & Roll, 1986).