Mass. Gen. Laws ch. 167J, § 15: Report of transfer of stock resulting in ownership of 10 per cent or more of outstanding stock with voting power

Section 15. The registrar, transfer agent or other officer or agent of any such stock corporation having charge of its stockholders' records or ledger shall, within 10 days after recording thereon any transfer of stock of the corporation which makes the transferee the owner of record of 10 per cent or more of the outstanding stock with voting power, report such transfer to the commissioner. Any agent or broker holding 10 per cent or more of such stock for the benefit of 1 or more persons shall, upon written request of the commissioner, report to the commissioner the names of such persons. Whoever violates this section shall be punished by a fine of not more than $500 or by imprisonment for not more than 6 months, or both.