California Code, Business and Professions Code - BPC § 16802

No trust, combination, or conspiracy shall be organized or exist in this State to prevent any person or corporation from selling livestock on commission at such rate as the person or corporation may see fit to charge. Any rule, regulation, by-law, or agreement of any corporation, association, society, or combination of persons, whereby any such parties are required to charge not less than a given sum for commissions, or whereby any person or commission merchant is, in any respect, restrained from charging less than a certain fixed sum for his services as such commission merchant in the sale of livestock, is declared to be contrary to the public policy of this State, and is unlawful.

Any person who enters into any such trust, combination, or conspiracy, or who enforces or aids, abets, assists, or encourages the enforcement of any such rule, regulation, by-law, or agreement, is liable to the penalties prescribed in this chapter.