Hedge fund attributes and volatility around equity offerings

Research paper by Robert M. Hull, Sungkyu Kwak, Rosemary Walker

Indexed on: 10 Jan '12Published on: 10 Jan '12Published in: Journal of Economics and Finance


The purpose of this paper is to explore the potential influence of hedge fund attributes on idiosyncratic volatility (IVOL) in excess stock returns for 705 firms undergoing seasoned equity offerings (SEOs). This investigation is important due to the pervasive concerns about the impact of hedge funds on volatility. We choose a time frame from 1999 to 2005 covering two periods that could impact IVOL differently: the internet-technology bubble period and the post-bubble period. Our time frame includes the breakpoint year of 2000 that marks a downward trend in IVOL from 2000 to 2008. We explore this IVOL drop for a sample of SEOs and find that the decline in IVOL for this sample can be primarily related to the rapid increase in the hedge fund industry size and to the increasing use of leverage by hedge funds. This trend is also related to the increasing use of a relative value (arbitrage) strategy and the decreasing use of an event-driven strategy. IVOL for our sample also appears to decrease with greater hedge fund performance except when hedge funds are riding the pre-SEO stock price run-up. The downward shift in IVOL for our SEO sample around their offering dates is better explained by hedge fund attributes than by non-hedge fund attributes. In conclusion, our findings suggest that the rapid increase in the hedge fund industry offer an explanation for the mysterious decline in IVOL that has been witnessed since 2000.