California Code, Government Code - GOV § 50026.5

(a) The legislative body of any local agency, chartered or general law, which is otherwise authorized by law or charter to impose any tax, shall not impose any tax, fee, or charge on or measured by the sale of any stocks, bonds, or any other securities.

(b) It is the intent of the Legislature to prohibit any imposition of any local tax, fee, or charge, in connection with the sale of those securities, whether that imposition is imposed on the transaction itself, on the privilege of engaging in any transaction, or in any other form.

(c) The Legislature finds and declares that the need for uniform statewide regulation and taxation of securities transactions is a matter of statewide concern, and it is the Legislature's intent to regulate the subject matter of securities comprehensively and to occupy the field to the exclusion of local action.