Okla. Stat. tit. 60, § 1307

Investment trust advisors - Qualifications - Powers. Any person may serve as an investment trust advisor, notwithstanding that the person is the transferor of the qualified disposition, but a transferor may not otherwise serve as a fiduciary under a trust instrument except as stated in paragraph 2 of subsection A of Section 21 of this act. While serving as an investment trust advisor of the trust, the person may have all powers authorized by statute or by the trust instrument, including the power to vote by proxy any stock owned by the trust.