Impact Day

DEFINITION of 'Impact Day'

The date on which a corporation makes a secondary offering of its shares available for sale to the public. Such a secondary offering increases the total number of outstanding shares, therefore, existing shareholders will own a smaller percentage of the company and earnings per share will decline. As a result of these changes, the stock's price may decline on, or shortly after, impact day.


The purpose of a secondary offering, also called an add-on, could be to raise capital for a new project or business expansion or to increase working capital. As with an initial public offering, an underwriter will assist the company in determining the number of shares to offer, establishing a share price and selecting the right date for impact day.