Form S-4

DEFINITION of 'Form S-4'

A form that must be submitted to the Securities and Exchange Commission in the event of a merger or an acquisition between two companies. The form must also be submitted for exchange offers.


An exchange offer occurs when a company or a financial institution offers to exchange securities that it provides for similar securities at less demanding terms. This is often done in an attempt to avoid bankruptcy.

Submissions of this form are closely watched by investors who attempt to make quick gains from M&A activity.