DEFINITION of Impact Day

Impact day has been used to describe the date a company announces a dilutive secondary offering, or add-on, of new shares to the public, which may cause the share price to fall.


Because impact days increase the total number of outstanding shares, it leads to dilution, reducing existing shareholders’ share of the company, and earnings per share – which has an impact on the stock’s price.

Secondary offerings are used to raise additional capital, whether to expand the business or 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.