Notwithstanding , the trustee shall assume or reject, under , any executory contract of the debtor for the purchase or sale of a security in the ordinary course of the debtor’s business, within a reasonable time after the date of the order for relief, but not to exceed 30 days. If the trustee does not assume such a contract within such time, such contract is rejected.section 365(d)(1) of this titlesection 365 of this title