Newsom Signs California COMPETE Act Extending Cartwright Act to Single-Firm Conduct
California's new COMPETE Act extends the Cartwright Act to unilateral conduct, giving the state attorney general and private plaintiffs a new theory of liability in a state seen as a national antitrust testing ground.
On September 30, 2026, Governor Gavin Newsom signed Assembly Bill 1776, the COMPETE Act, which California practitioners describe as extending the Cartwright Act to reach single-firm conduct. The significance is not cosmetic. California is the most active state venue for antitrust enforcement and private suits, and the attorney general has repeatedly used it to press theories federal law — notably Sherman Act Section 2 — has not embraced or has narrowed. A statutory route to liability for unilateral conduct would let plaintiffs and the AG proceed without proving a relevant market, monopoly power, or exclusionary agreements, lowering the burden in a state where such suits are already frequent.
Exposure is direct and derivative. Companies already defending California claims face an additional or alternative cause of action, and out-of-state companies face new venue risk in a plaintiff-friendly forum. Conduct lawful federally can still draw scrutiny under a broader state standard, complicating national and global settlement strategy.
The details that matter most — the elements of the new standard, exemptions and carve-outs, treatment of federally lawful conduct, retroactivity, and effect on pending cases — are not in the available reporting, which is limited to the signing announcement. Counsel should await the statutory text and early litigation.