Finances
Equity Trader Alert #2025 – 82 Nasdaq Weekend Testing for SEC Round Lot Changes
As previously announced in UTP Vendor Alert 2025-10, starting November 3rd 2025, the SEC will adopt new definitions for “Round Lot” information under the Market Data Infrastructure (MDI) Rules to enhance the transparency for investors and other market participants of quotes and orders in NMS stocks.
The Nasdaq Stock Market (Nasdaq), Nasdaq BX, and Nasdaq PSX will support testing of the round lot changes during the following industry-wide Saturday testing dates:
- October 18th
- November 1st (confidence test)
The list of Nasdaq-listed securities available for testing can be found in UTP Vendor Alert 2025-20.
For any questions, please contact Nasdaq Trading Services at +1 212 231 5180.


