A bank may, directly or through subsidiaries, purchase or sell without recourse any security upon the order of a customer for his account. The terms of this section shall be construed to permit banks to contract with securities brokerage services. Source: SL 1969, ch 11 , § 4.7; SDCL, § 51-18-7; SL 1988, ch 377 , § 87; SDCL, § 51-18-1.1.