California's COMPETE Act Codifies Single-Firm Conduct, Prosecutors Only
California's COMPETE Act extends the Cartwright Act to single-firm monopolization and monopsony from January 1, 2027, but only prosecutors can sue and there is no private right of action.
On September 30, 2026, Governor Newsom signed AB 1776, the COMPETE Act, adding Business and Professions Code Sections 16730 through 16732 and, for the first time in California, extending the Cartwright Act to monopolization and monopsonization by a single firm, effective January 1, 2027. The enacted text is materially narrower than the Law Revision Commission's proposal: there is no private right of action and a Cartwright Act violation cannot be used as an Unfair Competition Law predicate, so only the Attorney General or a district attorney may sue. Section 16731 tracks Sherman Act Section 2, requires proof of substantial market power, and directs courts to the In Re Cipro framework, while federal law is now "at most instructive." Cartwright Act civil penalties of up to $1 million per violation plus mandatory restorative injunctions are available, and the express monopsony language points to single-employer conduct in labor markets, with a small-business and supervised-agency carve-out. Counsel should assess dominance and buyer-side concentration in California-facing operations now, monitor how courts adapt Cipro to unilateral conduct, and track the parallel California measures on common pricing algorithms, Cartwright Act penalties, and premerger notification applicable to filings on or after January 1, 2027.