Corporate insiders – meaning a company's officers and directors, and any beneficial owners of more than ten percent of a class of the company's equity securities registered under Section 12 of the Securities Exchange Act of 1934 – must file with the SEC a statement of ownership regarding those securities. 

The initial filing is on Form 3. An insider of an issuer that is registering equity securities for the first time under Section 12 of the Exchange Act must file this Form no later than the effective date of the registration statement. If the issuer is already registered under Section 12, the insider must file a Form 3 within ten days of becoming an officer, director, or beneficial owner.

Changes in ownership are reported on Form 4 and must be reported to the SEC within two business days. You can find the limited categories of transactions not subject to the two-day reporting requirement in the new rule.

Insiders must file a Form 5 to report any transactions that should have been reported earlier on a Form 4 or were eligible for deferred reporting. If a Form must be filed, it is due 45 days after the end of the company's fiscal year.

For more information on the reporting requirements for officers, directors, and beneficial owners, you can read Section 16 of the Exchange Act. You can download blank PDF versions of Form 3, Form 4, and Form 5 as well as the instructions to these Forms.