This study examines the effect of issuing common stock on shareholder wealth under two alternative methods of registration, shelf registration under the Securities and Exchange Commission's Rule 415 and the traditional method of registering shares for immediate sale. The stock price reactions accompanying security registrations and offerings over the period from March 1982 through November 1983 are examined for over two hundred issues. A negative price reaction is observed for traditional and shelf registrations for both utility and non‐utility issuers. No statistically significant difference is observed between shelf and traditional registrations. Further negative price reactions precede the offerings of these securities.