The U.S. Securities and Exchange Commission (SEC) was established to protect investors, maintain fair, orderly, and efficient markets, and facilitate capital formation.

The laws and rules that govern the securities industry in the United States derive from a simple and straightforward concept: all investors, whether large institutions or private individuals, should have access to certain basic facts about an investment prior to buying it, and so long as they hold it. To achieve this, the SEC requires public companies to disclose meaningful financial and other information to the public. This provides a common pool of knowledge for all investors to use to judge for themselves whether to buy, sell, or hold a particular security. Only through the steady flow of timely, comprehensive, and accurate information can people make sound investment decisions.

The SEC oversees the key participants in the securities world, including securities exchanges, securities brokers and dealers, investment advisors, and mutual funds. Here the SEC is concerned primarily with promoting the disclosure of important market-related information, maintaining fair dealing, and protecting against fraud.
The SEC's foundation was laid in an era that was ripe for reform. Before the Great Crash of 1929, there was little support for federal regulation of the securities markets. This was particularly true during the post-World War I surge of securities activity. Proposals that the federal government require financial disclosure and prevent the fraudulent sale of stock were never seriously pursued.

It is the responsibility of the Commission to:

• interpret federal securities laws;
• issue new rules and amend existing rules;
• oversee the inspection of securities firms, brokers, investment advisers, and ratings agencies;
• oversee private regulatory organizations in the securities, accounting, and auditing fields; and
• coordinate U.S. securities regulation with federal, state, and foreign authorities.