Public Company Accounting Oversight Board
The Public Company Accounting Oversight Board (PCAOB) is a nonprofit corporation created by the Sarbanes–Oxley Act of 2002 to oversee the audits of US-listed public companies. The PCAOB also oversees the audits of broker-dealers, including compliance reports filed pursuant to federal securities laws, to promote investor protection.
Source: Wikipedia — Public Company Accounting Oversight Board (CC BY-SA 4.0)