Alerts and Notices Trader Alerts

Trader Alert 22-02: New Strict Order Entry Validations Effective Monday, February 28 and UAT testing on Saturday, February 26, 2022

On Monday, February 28, 2022, MEMX plans to make the following updates to order entry validations. These updates are currently available in the MDE test facility and will be available in production during the Saturday, February 26, 2022, UAT.

  1. If a request has one or more reserve order tags set then all the required reserve order tags must be set or the request will be rejected. Two exceptions are: (see below table for more details)
    1. If DisplayQty = OrderQty and no other reserve order tags are set the request will be accepted.
    2. If Display Qty = 0 and the order is hidden and no other reserve order tags are set the request will be accepted.
  2. If ExpireTime is set and TimeInForce is not GoodForTime then the request will be rejected.
  3. If MinQty < 1 then the request will be rejected.
DisplayQty (1)DisplayMethod (1)ReserveReplenishmentTimeType (1)DisplayMinIncr (2)Current BehaviorStrict Validation Behavior
< OrderQty and > 0Initial or RandomizeBySizeImmediate or RandomPositive NumberAcceptAccept
= OrderQtyNot DefinedNot DefinedNot DefinedAcceptAccept
> 0 Undisclosed (hidden)Not DefinedNot DefinedAcceptReject
= 0 Undisclosed (hidden)Not DefinedNot DefinedAcceptAccept
Not DefinedInitial or RandomizeBySizeNot DefinedNot DefinedRejectReject
< OrderQty and > 0 (3)Not DefinedImmediate or Random (3)Positive Number (3)AcceptReject

(1) Required reserve order tags.

(2) DisplayMinIncr required only if DisplayMethod = RandomizeBySize.

(3) If any combination of these tags are defined the current behavior is to accept the request and process as a non reserve order. After Strict Validation is enabled these requests will be rejected.

Test Schedule for Saturday, February 26, 2022:

Time (Eastern)Trading Status
9:00A Session Available, Pre-Market
9:30A Market
12:00P Session Closed

Our Market Operations and Member Experience teams are here for any of your questions.  

MEMX Market Operations


MEMX Member Experience