VALUATION EFFECTS OF SECURITY OFFERINGS AND THE
ISSUANCE PROCESS
Wayne H. MIKKELSON and M. Megan PARTCH*
Unwersity o/Oregon, Eugene, OR 97403-1208, USA
Received January 1985, final version received July 1985
This study examines the stock price effects of security offerings and investigates the nature of
information inferred by investors from offering announcements. Changes in share price are
unrelated to characteristics of offerings such as the net amount of new financing, relative offering
size, and the quality rating of debt issues. The type of security is the only significant determinant of
the price response. The opposite patterns of abnormal stock returns following the announcement
of completed versus cancelled offerings suggest that managers issue common stock or convertible
debt when in managers’ view shares are overpriced.
1. Introduction
Recent studies document significant average stock price reactions to the
announcement of changes in capital structure. ’ However, despite the extensive
evidence, our understanding of the determinants of these price effects is quite
limited. Most authors conclude that the stock price reaction reflects more than
the direct effects of the capital structure change on the firm’s cash flows.
“We are grateful to Paul Asquith, Paul Healy, Ron Masulis, John McConnell, Cliff Smith, the
participants of finance seminars at the University of Oregon and the University of Washington,
and Ken French (the referee) for helpful comments and to B. Briggs and C. Rejali for research
assistance.
‘Masulis (1980a) finds an increase in share price at the announcement of intrafirm exchange
offers when shares are retired and a decrease in share price when shares are issued. Dann (1981)
Masulis (1980b) and Vermaelen (1981) report a positive price effect at the announcement of
intratirm tender offers to repurchase shares. Masulis and Korwar (1986) and Asquith and Mullins
(1986) document a decline in share price at the announcement of common stock offerings, and
Dann and Mikkelson (1984) find a negative price effect for convertible debt offerings, Mikkelson
(1981) reports a negative share price response to calls of convertible debt that force conversion to
common stock.
Changes in the amount of straight debt outstanding are met with less pronounced effects on
share price. Dann and Mikkelson (1984) report a small and statistically insignificant stock price
decline in response to the announcement of public offerings of straight debt. Vu (1986) finds a
small, statistically insignificant average stock price reaction to the announcement of calls of
straight debt.