If the property consists of stock or securities the acquisition of which, or the contract or option to acquire which resulted in the nondeductibility (under La. Rev. Stat. 47:160 relating to wash sales) of the loss from the sale or other disposition of substantially identical stock or securities, then the basis shall be the basis of stock or securities so sold or disposed of, increased or decreased, as the case may be, by the difference, if any, between the prices at which the property was acquired and the price at which such substantially identical stock or securities were sold or otherwise disposed of.