The Investment Advisers Act of 1940 (US, 15 U.S.C. 80b)

The Investment Advisers Act regulates the manager, not the fund: anyone who, for compensation, is in the business of advising others on securities is an "investment adviser" and is caught. Its spine is registration (§203) — with the SEC above an assets-under-management threshold, otherwise at state level — and a broad anti-fraud, fiduciary-duty core (§206) that the SEC enforces hard. For private-fund managers the practical questions are the registration route and the exemptions: the private-fund adviser and venture-capital adviser exemptions produce "exempt reporting advisers" who still file, while larger managers register fully. It pairs with the Investment Company Act, which regulates the fund itself.

Scope and the core mechanism

The Act turns on the §202 definition of "investment adviser" and then allocates supervision by size: registration with the SEC above the AUM threshold, with the states below it (§203A). Whatever the route, the §206 anti-fraud and fiduciary obligation applies — the duty of care and loyalty the SEC reads into the adviser relationship, plus specific rules on custody, advertising and conflicts. Private-fund managers navigate the exemptions (private-fund adviser, venture-capital adviser, foreign private adviser) that create the "exempt reporting adviser" category — reduced registration, but still Form ADV filing and the anti-fraud rules. The full section text is searchable clause-by-clause through the regulation graph and ask-the-law.

The gotcha: the exemptions cut your registration burden, not your anti-fraud exposure — §206 and the fiduciary duty reach exempt reporting advisers too. "We're exempt" is not "we're unregulated".