Reminder - Cboe Equities Weekend and Certification Testing Support for Round Lot Requirement Changes

Reference ID: C2025101000

Applicable Cboe Exchanges: BYX Equities, BZX Equities, EDGA Equities, EDGX Equities

Overview

As previously announced, the Securities and Exchange Commission (SEC) will introduce new Round Lot Tier designations beginning November 3, 2025. To support these changes, all Cboe-affiliated U.S. Equities Exchanges will offer weekend testing opportunities beginning September 20, 2025. The complete test schedule is provided below.

In addition, the BZX Equities Exchange (BZX) certification environment is available for the test submission of quotes and trades to the Consolidated Tape Association (CTA) Securities Information Processors (SIPs) certification environment in configured Cboe-listed symbols.

Technical Details

Weekend Testing Schedule

To support member testing ahead of the November 3, 2025 launch date, Cboe will offer the following weekend test opportunities in all Cboe-affiliated U.S. Equities certification environments. The same Cboe-listed symbols with new round lot sizes supported in certification will be supported with the new round lot sizes during weekend testing. For a full list of supported symbols with new round lot sizes, please refer to the test plans published by the CTA and Unlisted Trading Privilege (UTP) SIPs.

Table 1. Weekend Testing Schedule
MilestoneDate
Weekend Test #109/20/25
Weekend Test #210/11/25
Weekend Test #310/18/25
Final Weekend Test11/01/25

Certification Testing Schedule

Effective immediately, members may begin testing in the BZX certification environment. Members may submit quotes and trades to the CTA SIP certification environment via the BZX certification environment using Cboe-listed symbols configured with the new round lot sizes. To view these new round lot size quotes and trades, members must connect to the CTA SIP certification environment.

Table 2. Round Lot Size Test Symbols
SymbolRound Lot Size
CBOE40
LIBD40
ZTEST10
ZTST1