Form 3 is an important document required by the US Securities and Exchange Commission (SEC). It is filed by any directors, officers, or major shareholders of a publicly registered company. The purpose of Form 3 is to provide disclosure of the ownership and other financial interests of the company's insiders. This information becomes available to the public, allowing investors to know who is behind the decisions of a given company.

The requirement of filing Form 3 is meant to prevent insider trading. An insider is defined as a person who, either directly or indirectly, has access to nonpublic information about the company. By filing the form, the insider is verifying that he/she has fully disclosed any such information and is not using it to their personal benefit.

Form 3 must be filed with the SEC no later than 10 days after an insider becomes affiliated with a company. It contains information about the insider, such as contact information, beneficial owner status, beneficial ownership of the company's securities, and the number of company securities they are holding. It also requires disclosure of the issuer's securities that the insider may have indirectly purchased or sold through the course of business.

The form also requires the disclosure of any ownership or transactions made by the insider within the past two years. This is to ensure that any insider transactions are properly documented and can be tracked over time to check if the insider is acting in the company's best interests.

The SEC also requires certain officers to complete an annual update of their Form 3. This includes reporting any changes in the insider's beneficial ownership, as well as any indirect transactions that may have occurred during the year. Companies must file Form 3 for all officers, directors, and major shareholders within their organization.

Ultimately, Form 3 is an important disclosure document that helps to inform investors and keep them updated on the activities and ownership of a company's insiders. By ensuring that all officers, directors, and major shareholders file this form, the SEC is able to scrutinize the activities of the company's insiders and ensure that they are acting in the best interests of the company and its shareholders.