Midpoint-or-better limit order
(57) Midpoint-or-better limit order means, with respect to an order received at a time when a national best bid and national best offer is being disseminated and the primary listing market has disseminated its first firm, uncrossed quotations in the security, any non-marketable buy order with a limit price that is equal to or higher than the midpoint of the national best bid and national best offer at the time of order receipt and any non-marketable sell order with a limit price that is equal to or lower than the midpoint of the national best bid and national best offer at the time of order receipt, and, with respect to an order received at a time when a national best bid and national best offer is not being disseminated, any non-marketable buy order with a limit price that is equal to or higher than the midpoint of the national best bid and national best offer at the time that the national best bid and national best offer is first disseminated after the time of order receipt, or any non-marketable sell order with a limit price that is equal to or lower than the midpoint of the national best bid and national best offer at the time that the national best bid and national best offer is first disseminated after the time of order receipt. For orders received at a time when the national best bid and national best offer is being disseminated but the primary listing market has not disseminated its first firm, uncrossed quotations in the security, whether an order is a midpoint-or-better limit order shall be determined from the time that the primary listing market disseminates its first firm, uncrossed quotations in the security.