Okla. Admin. Code § 660:11-11-49
By authority delegated to the Administrator in Section 1-203 of the Securities Act, the following transactions are determined to be classes of transactions for which registration is not necessary or appropriate for the protection of investors and are exempt from Sections 1-301 and 1-504 of the Securities Act: any nonissuer transaction involving a security issued and outstanding and listed or approved for listing upon notice of issuance on Tier 1 of the Chicago Stock Exchange or involving any security of the same issuer that is of senior or substantially equal rank, or that differs only in terms of voting rights, from the security so listed, or any warrant, option or right to purchase or subscribe to any such security so long as the standards for such listing remain substantially the same.
Okla. Admin. Code § 660:11-11-49