Notice of Filing and Immediate Effectiveness of Proposed Rule Change Temporarily Suspending the Requirements of Exchange Rule 311-Equities and Related Exchange Equities Rules Concerning the Approval of New Member Organizations and Exchange Rule 353 and Related Exchange Rules Concerning the Approval of New ATP Holders in Order To Approve Apex Clearing Corporation, f/k/a Ridge Clearing and Outsourcing Solutions, Inc. as an Exchange Equities Member Organization and ATP Holder, Subject to Apex Clearing Complying With Exchange Rules for a New Member Organization and ATP Holder Within 30 Calendar Days of the Date That Apex Clearing Is Provisionally Approved as an Exchange Equities Member Organization and ATP Holder