All contracts and agreements between customers and brokers respecting the purchase or sale either upon credit or margin of any securities, choses in action or commodities, of the character specifically referred to in section 46:34-1 of this title, wherein it is mutually understood and agreed by the parties thereto that the broker shall purchase or sell such securities, choses in action or commodities, as directed by the customer and for the account and risk of the customer, shall be valid and effective if such purchase or sale shall be actually made by the broker pursuant to such direction and for the account and risk of the customer, even though such purchase or sale may not be made in the customer’s name and even though as between the broker and customer the securities, choses in action or commodities so purchased or sold, may not have been actually delivered to or by such customer.