Okla. Stat. tit. 21, § 353

A. It shall be unlawful for any public officer or deputy or employee of such officer to either directly or indirectly, buy, barter for, or otherwise engage in any manner in the purchase of any bonds, warrants or any other evidence of indebtedness against this state, any subdivision thereof, or municipality therein, of which he is an officer. B. The provisions of this section shall not apply to those municipal officers and employees who are subject to Section 8-113 of Title 11 of the Oklahoma Statutes.