Existing law, commonly known as the Cartwright Act, identifies certain acts as unlawful restraints of trade and unlawful trusts and prescribes provisions for its enforcement. Chapter 338 of the Statutes of 2025 provides that in a complaint for any violation of the Cartwright Act, it is sufficient to contain factual allegations demonstrating that the existence of a contract, combination in the form of a trust, or conspiracy to restrain trade or commerce is plausible. Chapter 338 of the Statutes of 2025 also provides that a complaint for any violation of the Cartwright Act is not required to allege facts tending to exclude the possibility of independent action. Existing case law, In re Cipro Cases I & II (2015) 61 Cal.4th 116, establishes a rule of reason analysis for certain claims under the Cartwright Act, which, among other things, determines whether an act was made for the purpose of avoiding competition and whether the anticompetitive effects of the agreement outweigh any procompetitive justifications. This bill would prohibit any person from monopolizing or monopsonizing any part of trade or commerce, as provided. The bill would require courts to use the analytical framework and guidance provided in In re Cipro Cases I & II. The bill would require a plaintiff bringing an action under its provisions to allege, and prove at trial, substantial market power through either direct or indirect evidence. The bill would exempt a small business, as defined, from these provisions. The bill would provide that its provisions do not prevent, limit, or prohibit certain conduct and legal instruments, including exclusive franchises granted and supervised by a local, state, or federal governmental agency. This bill would require any action brought pursuant to these provisions to be initiated only by the Attorney General or a district attorney, and would, with certain exceptions, preclude an alleged violation under its provisions from serving as a predicate violation under the Unfair Competition Law. The bill would require an action brought pursuant to these provisions to be filed as a "complex case" pursuant to provisions of law requiring the assessment of additional court fees, as specified. The bill would also make related findings and declarations. The bill would require courts to liberally interpret California's antitrust laws to best promote free and fair competition, as provided. Because the bill would expand the scope of activities prohibited by the Cartwright Act, the violation of which is punishable as a crime, the bill would impose a state-mandated local program. The California Constitution requires the state to reimburse local agencies and school districts for certain costs mandated by the state. Statutory provisions establish procedures for making that reimbursement. This bill would provide that no reimbursement is required by this act for a specified reason.