# Cboe Titanium U.S. Equities/Options Web Portal Port Controls Specification

Version 1.4.34 · August 10, 2026

## Introduction

The Customer Web Portal allows customers to implement and modify a number of port-based risk management settings. The Customer Web Portal Logical Port Request tool can be used to submit requests to the Trade Desk to establish or change DROP Port Monitoring settings, while the Customer Web Portal Port Control tool allows customers to make on-the-fly changes to a number of other port-level risk attributes without the assistance of the Cboe Trade Desk.

### Customer Web Portal

All customers have the ability to access and use the Customer Web Portal Logical Port Request tool or Port Controls tool. This includes customers that connect directly, customers that reach Cboe through a Service Bureau, and firms that act as Sponsors.

Customers who desire access to the Customer Web Portal must first obtain an account. This can be accomplished by contacting your Customer Web Portal Administrator or by sending an email to the Cboe Trade Desk. After successfully logging in to your Web Portal account, users with the appropriate access will be able to click on the Logical Port Request link or Port Controls link in the menus on the left hand side of their account page.

## Port Controls

Customers may directly modify various port-level risk attributes via the Port Controls tool link within the Customer Web Portal.

_(Figure: Figure 1. Port Controls Tool Link)_

From this page, users may select the Firm ID and MPID/EFID (optional) of the ports they would like to edit settings for and proceed with configuration.

_(Figure: Figure 2. Port Controls Form (Options only))_

_(Figure: Figure 3. Port Controls Form (Equities only))_

### Selecting the Client

#### Direct

Ports that are owned by the customer and have customer-owned MPIDs allowed on these ports are considered direct connections to the Exchange. A customer can have multiple MPIDs enabled on a single port. The risk settings for each of these MPIDs must be updated separately within the Web Portal Port Controls even if these MPIDs use the same port. Note that in the example, member Bats Trading, Inc. has two MPIDs: BATS and BZXX.

_(Figure: Figure 1. Example of Multiple MPIDs Enabled on Single Port)_

#### Service Bureau

In a Service Bureau relationship a customer allows its MPID or EFID to be used on the ports of a technology provider, or Service Bureau. One MPID/EFID may be allowed on several different Service Bureaus. In these cases, a separate client relationship is created for each MPID/Service Bureau combination. Note the example where the BATS MPID is allowed on two separate service bureaus.

_(Figure: Figure 1. Example of Single MPID on Two Separate Service Bureaus)_

#### Sponsored Access

A Sponsored Access relationship consists of a Sponsoring customer and a Sponsored Participant. The Sponsoring customer is the MPID owner and is the only entity in this relationship with access to the Web Portal Port Controls. The Sponsored Participant owns the ports, but has no ability to make changes to its port-level risk settings using the Web Portal Port Controls.

_(Figure: Figure 1. Example of Sponsored Access Relationship)_

### Order Restriction

#### Intermarket Sweep Orders

Customers have the ability to allow, or restrict their ability to place Intermarket Sweep Orders (ISO) which do not check the NBBO for a trade through before executing on the local book. The default for this setting is to Allow ISO and can be changed by un-checking the corresponding box and saving the change.

#### Directed Intermarket Sweep Orders

Customers have the ability to allow, or restrict their ability to place Directed Intermarket Sweep Orders (Directed ISO) which do not check the NBBO for trade through before skipping the local book and routing directly to the specified away market center as an ISO order. The default for this setting is to Allow Directed ISO and can be changed by un-checking the corresponding box and saving the change. This feature functions separately from the Allow ISO check.

#### Short Sales (Equities only)

Customers have the ability to allow or restrict their ability to place Short Sale orders. The default for this setting is to allow Sell Short and Sell Short Exempt orders and can be changed by un-checking the corresponding box and saving the change.

#### Require LocateBroker on Short Sale Orders (Equities only)

Firms may choose to require LocateBroker (FIX Tag 5700) on all Sell Short and/or Sell Short Exempt orders. Orders will be rejected if not populated according to the port settings. For FIX and BOEv2 protocols, this setting also applies when amending a long sell order to a short or short exempt order. For BOEv3 protocol, all new short and/or short exempt orders as well as all amendments (i.e., amendments from long to short or short to short amendments) will require that LocateBroker is populated.

#### Require LocateBroker on Modified Short Sale Orders (Equities only)

Firms may choose to require LocateBroker (FIX Tag 5700) to be populated on all Sell Short and Sell Short Exempt modifications. Modifications will be rejected if not populated according to the port settings. This port control is only available for FIX and BOEv2 protocols.

#### Pre-Market Trading (Equities only)

Customers have the ability to allow or restrict their access to the Cboe Early and Pre-Market Trading session of 7:00 - 9:30 a.m. ET. The Early Trading session for EDGX begins at 4:00 a.m. ET. The default for this setting is to Allow Early and Pre-Market Trading and can be changed by un-checking the corresponding box and saving the change. Effective 12/07/26 for EDGX only, customers will have the ability to restrict trading in the Overnight Trading Session from 9:00 p.m. - 4:00 a.m. ET.

#### Post-Market Trading (Equities only)

Customers have the ability to allow or restrict their access to the Cboe Post-Market Trading session of 4:00 - 8:00 p.m. ET. The default for this setting is to Allow Post-Market Trading and can be changed by un-checking the corresponding box and saving the change.

#### Block New Orders

Customers have the ability to block all new inbound order flow across all sessions by checking the corresponding box and saving the change. Customers will still be able to send cancel requests in for resting orders.

#### Disallow Market Orders (Equities only)

Customers have the ability to allow or reject inbound Market orders during continuous trading. The default setting is to not restrict Market orders and it can be changed by selecting another option and saving the change. Market orders function as detailed below.

- Stop orders are treated as Market Orders during regular trading hours and will be rejected if the Disallow Market Orders port attribute is set to `2` or `3`.
- ROOC orders (RoutStrategy (FIX Tag 9400) (BZX and EDGX only) are accepted at all entry times if the Disallow Market Orders port attribute is set to `1` or `2`.
- Non-Cboe-listed securities opening times vary, so a Market Order may be accepted or rejected depending on security opening time, order receipt time, and Disallow Market Orders setting.
- MOO and MOC orders (BZX only) are always accepted regardless of the setting used.
- Stop limit and Peg orders are exempt from this functionality.

### Maximum Per-Order Limits

#### Max Quantity Per Order

This value is the max shares (Equities) or contracts (Options) per order and is implemented consistently across all of a customer’s current ports. When the specified limit is exceeded, the order is rejected. The value can be changed in real-time by entering the desired limit and saving the change. The default value for the Max Quantity Per Order is 25,000 for both Equities and Options.

#### Max Notional Value Per Order

This value is the maximum notional value per order and is implemented consistently across all of a customer’s ports. Note that notional value is calculated by multiplying the number of shares (contracts) by the order’s limit price. When the specified limit is exceeded on an order, the order is rejected. The value can be changed in real-time by entering the desired limit and saving the change. The default value for the Max Notional Value of an inbound order is unlimited.

### Duplicative Order Protection

Duplicative Order Protection provides customers with the ability to prevent consecutive duplicative orders where orders clearing the same EFID/MPID that have the same Side (Buy or not), Price, Quantity, and Symbol have been entered. Customers may set the following:

- the number of consecutive duplicate orders required to trigger the risk control on a specific port, and
- the action when encountered (reject offending orders or disable port).

When configuring the number of consecutive duplicate orders, setting the parameter to zero effectively turns off the Duplicative Order Protection check for a port. The Duplicative Order check compares each new order to the previous order sent. No time parameter is included.

If Disable Port is selected, ALL new orders received on the port for the EFID/MPID will be rejected until a request is submitted to the Trade Desk to reset the risk control on the port for the EFID/MPID. Cancels will continue to be processed for orders accepted prior to tripping the Duplicative Order Protection check.

Example: If a customer sets the number of orders to ten (10), the system will compare each new order against the previous order sent. The system will take the defined action (reject or disable the port) when 10 or more duplicate orders have been sent in a row.

Duplicative Order Protection checks are only performed at the individual session level.

### Single Order ADV Check

The Single Order ADV Check causes orders to be rejected if they exceed a specified percent of the 20 day ADV for the stock. Integer values between 1 and 100 are permitted. If no value is entered, the check is not enabled.

Customers can additionally specify whether the Single Order ADV Check should only be applied in cases when the stock’s 20 day ADV is greater than or equal to a specified number of shares. If no value is supplied, the check will be applied in all cases regardless of the stock’s 20 day ADV.

### Message Rate Limits

#### Port Message Rate Threshold (Equities Only)

The Port Message Rate Threshold value is the maximum number of messages that can be sent on a single session in a rolling one second window, calculated from the time a non-heartbeat message is received. When the the value is exceeded, new orders will be rejected, modifies will be treated as cancels, and cancels will continue to be processed. The default value is 5000 messages per second.

#### Symbol Message Rate Threshold (Equities Only)

The Symbol Message Rate Threshold value is the maximum number of messages that can be sent for a symbol on a single session in a rolling one second window, calculated from the time a non-heartbeat message is received. When the value is exceeded, new orders will be rejected, modifies will be treated as cancels, and cancels will continue to be processed. The default value is 5000 messages per second.

#### Enforce Rate Limit via Pause (Equities Only)

When Enforce Rate Limit via Pause is set to False, the existing Port Order Rate Threshold, Sustained Port Order Rate Threshold, Symbol Order Rate Threshold, and Sustained Symbol Order Rate Threshold port attributes will be enforced by rejects (as described). When Enforce Rate Limit via Pause is set to True, Port Order Rate Threshold, Sustained Port Order Rate Threshold, Symbol Order Rate Threshold, and Sustained Symbol Order Rate Threshold port attributes will be enforced by read pause instead of by rejects.

If Enforce Rate Limit via Pause is set and the Port Order Rate Threshold, Sustained Port Order Rate Threshold, Symbol Order Rate Threshold, or Sustained Symbol Order Rate Threshold port attributes rate limit is exceeded, the system will pause the reading of all new messages (including cancels) that exceed the the limit until the pause timer has expired. Once the pause timer has expired, the system will resume reading orders again.

### Fat Finger Protection

Fat Finger Protection allows customers to have orders rejected if the limit price on the order is priced too aggressively through the NBBO. Customers may configure Fat Finger limits using both percentage-based limits and dollar-based limits. Different Fat Finger limits may be specified across distinct limit price ranges to allow customers flexibility in setting up Fat Finger Protection. In a scenario where both a percentage-based limit and a dollar-based limit are specified, the least restrictive value will always be applied. Does not apply to RHO orders entered prior to the open until they move to continuous trading. The Fat Finger settings will be applied to both single leg and complex orders. Fat Finger Protection is not applicable for Stop Limit Orders. Fat Finger Protection is not applicable for floor-based Multi-Class Spread limit orders. Fat Finger checks are applicable to SPX versus SPXW orders as they are eligible for electronic routing.

For Equities only, when the NBBO is unavailable, all orders with a limit price will use Last Sale as the reference price instead of the opposite side of the NBBO if the latter is not available. If Last Sale is also not available, the reference price will be the previous day’s Official Closing Price.

For Options only, if the opposite side NBBO is unavailable, no checks are performed unless during GTH. During GTH, the last best local displayed price will be used, or the previous day closing NBBO midpoint if that is unavailable.

For unpriced orders (excluding MOO and MOC), customers can specify to reject the order if the opposite side of the NBBO is not available upon order entry. This would apply to market orders, unpriced peg orders, and triggered stop orders as well.

#### Percentage-Based Limits

Percentage-based limit price thresholds will reject any order whose limit price is more aggressive than a set percentage away from the opposite side of the NBBO at the time of entry. The percentage may vary across the different price ranges.

#### Dollar-Based Limits

Dollar-based limit price thresholds will reject any order whose limit price is more than a specified price range away from the NBBO at the time of entry. The dollar value may vary across the different price ranges.

#### Equity Price Ranges and Limits

The following price ranges have been defined to allow Equity customers’ flexibility in setting Fat Finger limits. Fat Finger protections are disabled by default in Equities and any Limits set by a customer are subject to the Fat Finger % Max values defined in the table that follows.

**Table 1. Equity Price Ranges and Fat Finger Limits**

| Limit Price Range | Fat Finger % | Fat Finger % Max Limit | Fat Finger Dollar-Based Limit |
|---|---|---|---|
| Limit Price < $1 | Disabled | 500% | Disabled |
| ≥ $1 Limit Price but < $10 | Disabled | 50% | Disabled |
| ≥ $10 Limit Price but < $50 | Disabled | 20% | Disabled |
| ≥ $50 Limit Price but < $100 | Disabled | 20% | Disabled |
| ≥ $100 Limit Price but < $500 | Disabled | 20% | Disabled |
| Limit Price ≥ $500 | Disabled | 20% | Not Valid |

#### Options Price Ranges and Limits

The following price ranges have been defined to allow BZX Options, Cboe Options (C1), C2 Options, and EDGX Options customers flexibility in setting Fat Finger limits. BZX, C1, C2, and EDGX Options will have required, default Fat Finger Protections for both the pre-open and regular sessions. Customers can set more or less restrictive settings than the Exchange defaults defined below via the Port Controls tool. The following Exchange defaults will be applied if not specified by user:

**Table 1. Pre-Open Curb/GTH Session (Eligible GTH Products, Excluding SPXEligible GTH Products, Excluding Exception Classes)**

| Limit Price Range | Fat Finger % Default | Fat Finger Dollar-Based Limit Default |
|---|---|---|
| $0.00 - $1.99 | No Value | $1.00 |
| $2.00 - $5.00 | No Value | $1.50 |
| $5.01 - $10.00 | No Value | $2.00 |
| $10.01 - $20.00 | No Value | $3.00 |
| $20.01 - $50.00 | No Value | $4.00 |
| $50.01 - $100.00 | No Value | $6.00 |
| $100.01 & Above | 8% | Not Valid |

*Pre-Open Fat Finger checks will not be applied to orders with OrderCapacity=`M` or `N`.

**Table 2. Regular Session (Excluding Exception Classes)**

| Limit Price Range | Fat Finger % Default | Fat Finger Dollar-Based Limit Default |
|---|---|---|
| $0.00 - $1.99 | No Value | $0.50 |
| $2.00 - $5.00 | No Value | $0.75 |
| $5.01 - $10.00 | No Value | $1.00 |
| $10.01 - $20.00 | No Value | $1.50 |
| $20.01 - $50.00 | No Value | $2.00 |
| $50.01 - $100.00 | No Value | $3.00 |
| $100.01 & Above | 4% | Not Valid |

SPX and SPXW are currently considered Exception Classes and have unique Fat Finger default values for the Pre-Open and Regular sessions:

**Table 3. Exception Class Pre-Open Curb/GTH Session (SPX)**

| Limit Price Range | Fat Finger % Default | Fat Finger Dollar-Based Limit Default |
|---|---|---|
| $0.00 - $1.99 | No Value | $15.00 |
| $2.00 - $5.00 | No Value | $15.00 |
| $5.01 - $10.00 | No Value | $15.00 |
| $10.01 - $20.00 | No Value | $15.00 |
| $20.01 - $50.00 | No Value | $20.00 |
| $50.01 - $100.00 | No Value | $20.00 |
| $100.01 & Above | No Value | $25.00 |

**Table 4. Exception Classes: Regular Session (SPX)**

| Limit Price Range | Fat Finger % Default | Fat Finger Dollar-Based Limit Default |
|---|---|---|
| $0.00 - $1.99 | No Value | $1.00 |
| $2.00 - $5.00 | No Value | $1.50 |
| $5.01 - $10.00 | No Value | $2.00 |
| $10.01 - $20.00 | No Value | $3.00 |
| $20.01 - $50.00 | No Value | $4.00 |
| $50.01 - $100.00 | No Value | $6.00 |
| $100.01 & Above | 16% | Not Valid |

### Easy-to-Borrow List Management (Equities only)

The Easy-to-Borrow List allows Members to identify securities eligible for short sales on the Exchange, at a per security level. When no list is present and Short Sales are allowed for the customer, all securities are eligible for short sales. If a list is present and the security is not in the list, the order is rejected. Appropriately formatted symbol lists are text files with one symbol on each line and are uploaded using the Upload button under the Easy-to-Borrow Symbol List heading. The customer is also able to view the current list that is in place or clear the list entirely through this component. Firms cannot have both the Easy-to-Borrow List and Hard-to-Borrow List in place at the same time for order management.

### Hard-to-Borrow List Management (Equities only)

The Hard-to-Borrow List allows Members to identify securities ineligible for short sales on the Exchange, at a per security level. When no list is present and Short Sales are allowed for the customer, all securities are eligible for short sales. If a list is present and the security is not in the list, the order is accepted. Appropriately formatted symbol lists are text files with one symbol on each line and are uploaded using the Upload button under the Hard-to-Borrow Symbol List heading. The customer is also able to view the current list that is in place or clear the list entirely through this component. Firms cannot have both the Hard-to-Borrow List and Easy-to-Borrow List in place at the same time for order management.

### Restricted Symbol List Management (Equities only)

Customers have the capability to allow or restrict their ability to enter a security which is restricted due to insider holding status or any other SEC mandated regulations defining its restricted status. Symbol lists are submitted via text file with one symbol per line and uploaded within the Web Portal Port Controls tool. A customer is also able to view the current list that is in place or clear the list entirely through this component.

### Order Cut-offs (Kill Switch)

The following section demonstrates the types of cut-offs which can be performed using the Web Portal Port Controls. Note, a customer can block new order flow without pulling existing orders from the market by selecting the Block New Orders checkbox in the Order Restriction section of the page.

#### Cancel on Disconnect

Customers have the ability to configure their ports optionally to automatically cancel all open orders if no messages have been received from the customer for two heartbeat intervals. This is done to prevent orders from being stuck in an unknown state in the event of telecommunications failure. Options customers will have the ability configure Cancel on Disconnect to cancel all open orders or to exclude GTCs.

#### Market Maker Reject if Cancel on Disconnect Disabled (Options only)

Customers may optionally configure Market Maker Reject if Cancel on Disconnect is disabled. If configured, Market Maker and Away Market Maker capacity orders will be rejected if session (or firm) level Cancel on Disconnect is not enabled. Non-Market Maker capacity orders will be unaffected with this configuration.

#### Cancel All Open Orders

Customers have the ability to cancel all of their existing orders in real-time.

#### Cancel All Open Orders Excluding GTCs

Options customers have the ability to cancel all of their existing orders, excluding GTCs, in real-time.

#### Cancel All Open Orders and Block New Orders

Customers also have the ability to simultaneously prevent new order flow and cancel all existing orders in real-time.

### Automation

Automation of the Web Portal Port Controls is available through Secure Web API. Information on the implementation of the Secure Web API can be found Cboe Titanium U.S. Secure Web API.

## Contact Details

If you have any questions or would like to begin using the Web Portal Port Controls, please contact your account manager or the Cboe Trade Desk.

## Revision History

| Document Version | Date | Description |
|---|---|---|
| 1.0.0 | 10/12/12 | Initial version. |
| 1.0.1 | 11/13/13 | Add "Kill Switch" reference to existing Order Cut-off section. |
| 1.0.2 | 01/30/14 | Defined maximum value of 20% to Fat Finger Protection. |
| 1.0.3 | 02/06/15 | Updated Fat Finger Protection to include dollar-based limits and multiple price range support. |
| 1.0.4 | 02/20/15 | Added Duplicative Order Check section. Available effective 2/20/15. |
| 1.1.0 | 04/14/15 | Added Drop Port Monitoring section. |
| 1.1.1 | 08/06/15 | Added Single Order ADV Check section. |
| 1.2.0 | 02/19/16 | Bats branding/logo changes. |
| 1.2.1 | 04/25/16 | Clarified when Fat Finger Protection is applied |
| 1.2.2 | 05/05/16 | Added Warning Percentage Features for Aggregated Credit Limit Risk Management |
| 1.2.3 | 05/23/16 | Updated Fat Finger Protection behavior to use least restrictive value when both Percentage-Based and Dollar-Based Collars are specified. Also updated maximum allowable Percentage-Based Collar for limit prices less than $1 to 500%. Available effective 05/27/16 for EDGX Options Only. |
| 1.2.4 | 05/24/16 | Updated Fat Finger Protection behavior to use least restrictive value when both Percentage-Based and Dollar-Based Collars are specified. Also updated maximum allowable Percentage-Based Collar for limit prices less than $1 to 500%. Available effective 06/10/16 on all Bats Exchanges. |
| 1.2.5 | 06/07/16 | Updated Fat Finger Price Ranges and Limits section to include support for Options Members to opt-in to Exchange defined defaults. Available effective 06/17/16. |
| 1.2.6 | 12/06/16 | Update Cancel on Disconnect and Market Maker Reject if Cancel on Disconnect disabled. |
| 1.3.0 | 09/01/17 | Added Fat Finger defaults and ranges for C2 in support of its transition to the Bats technology trading platform. Removed DROP Port Monitoring Section. |
| 1.3.1 | 09/15/17 | Updated Fat Finger defaults for Pre-Open and Regular Session for C2. |
| 1.3.2 | 10/17/17 | Cboe branding/logo changes. |
| 1.3.3 | 11/7/17 | Updated Fat Finger defaults effective in BZX Options and EDGX Options effective in Feature Pack 2 on 12/8/17. |
| 1.3.4 | 12/06/17 | Updated effective date of Feature Pack 2 to 12/15/17. |
| 1.3.5 | 02/02/18 | Updated Equities Fat Finger Protection to detail how Fat Finger limits are handled when the NBBO is not available (effective 2/16/18). |
| 1.3.6 | 03/22/18 | Added clarification that Pre-Open Fat Finger Checks will not apply to order with a capacity of ‘M’ or ‘N’. Removed C2 Only references from GTC port coltrols. |
| 1.4.0 | 11/16/18 | Added support for Cboe Options Exchange. |
| 1.4.1 | 03/13/19 | Updated the times for the Pre-Market and Post-Market. |
| 1.4.2 | 05/17/19 | Added Message Rate Limits section and added Allow Directed ISO as an option under the Order Restrictions section. |
| 1.4.3 | 11/22/19 | Updated Fat Finger Check description to indicate these risk checks are not applied to Stop Limit Orders (effective on EDGX 12/2/19, effective on BZX, C1, C2 12/3/19). |
| 1.4.4 | 04/27/20 | Noted notional exposure tracking to be deprecated on Options effective 5/8/20. |
| 1.4.5 | 10/21/20 | Removed effective dates for released features. |
| 1.4.6 | 11/13/20 | Added note indicating the Early Trading session for EDGX will begin at 4:00 a.m. effective 12/7/20 (EDGX Only). |
| 1.4.7 | 12/04/20 | Updated effective date for Early Trading session on EDGX to begin at 4:00 a.m. to TBD (EDGX Only). |
| 1.4.8 | 02/08/21 | Updated effective date for Early Trading session on EDGX to begin at 4:00 a.m. to 03/08/21 (EDGX Only). |
| 1.4.9 | 03/25/21 | Added new section " Multi-Segment Holiday Day Order Handling" (C1 Only) (effective 09/27/21 Q3 2021) |
| 1.4.10 | 04/05/21 | Added noted indicating Fat Finger Protection will not be applicable for floor-based Multi-Class Spread limit orders (effective 04/21/21). |
| 1.4.11 | 04/29/21 | Noted for Options only, if the opposite side NBBO is unavailable, no checks are performed unless during GTH. |
| 1.4.12 | 05/13/21 | Updated effective date for Multi-Segment Holiday Day Order Handling to 09/27/21. |
| 1.4.13 | 09/09/21 | Removed " Multi-Segment Holiday Day Order Handling" section as this functionality is not accessible via the Port Controls tool. Added new section 2.10 "Hard-to-Borrow List Management (Equities Only)" to support the Hard-to-Borrow List functionality (effective 01/26/22 TBD 09/29/21 ). |
| 1.4.14 | 10/04/21 | Updated hyperlinks to technical specifications. Updated Hard-to-Borrow List Management (Equities Only) effective date to 01/26/22 TBD . |
| 1.4.15 | 11/04/21 | Updated Duplicative Order Check section (effective 12/07/21). |
| 1.4.16 | 12/16/21 | Added an Equities only screenshot to the Port Controls section for the Duplicative Order Check (effective 12/07/21). |
| 1.4.17 | 01/14/22 | Updated effective date for Hard-to-Borrow List to effective 01/26/22. |
| 1.4.18 | 01/21/22 | Updated Duplicative Order Check section for Options (effective 02/27/22). |
| 1.4.19 | 08/19/22 | Added Require LocateBroker port control. Short Sales port control will allow firms to reject Short Sell Exempt or Short Sell orders separately (Equities only) (effective 10/14/22). |
| 1.4.20 | 11/07/22 | Added XSP to the Pre-Open GTH/Curb Fat Finger Limits table (effective 12/11/22). |
| 1.4.21 | 11/11/22 | Updated screenshots in section 2.0. |
| 1.4.22 | 09/13/23 | Added Disallow Market Orders (Equities only) section (effective 10/13/23). |
| 1.4.23 | 09/20/24 | Aggregated Credit Limit Risk Management via a given port will be sunset on 01/30/26 12/31/25 at a future date. |
| 1.4.24 | 01/15/25 | Updated with Cboe Titanium branding. |
| 1.4.25 | 02/27/25 | Updated Aggregated Credit Limit Risk Management sunset date to 01/30/26 12/31/25 |
| 1.4.26 | 05/30/25 | Added new Enforce Rate Limit via Pause (Equities only) Message Rate Limit (effective 06/27/25). |
| 1.4.27 | 12/16/25 | Updated Aggregated Credit Limit Risk Management sunset date to 01/30/26. |
| 1.4.28 | 01/16/26 | Added Require LocateBroker on New and Modified Short Sale Orders (effective 02/02/26). |
| 1.4.29 | 01/20/26 | Updated tables in Options Price Ranges and Limits to clarify relevant products. |
| 1.4.30 | 01/30/26 | Updated name for Require LocateBroker on Modified Short Sale Orders. |
| 1.4.31 | 04/15/26 | Updated Options Price Ranges and Limits to reflect planned expansion of C1 trading hours for select equity options, including the addition of a morning Global Trading Hours (GTH) session and afternoon Curb session, subject to regulatory review (effective 07/13/26 08/17/26 TBD). |
| 1.4.32 | 06/12/26 | Updated planned expansion of C1 trading hours for select equity options to 08/17/26. |
| 1.4.33 | 06/30/26 | Noted in Pre-Market Trading (Equities Only) that EDGX customers will have the ability to restrict trading in the Overnight Trading Session (effective 12/07/26). |
| 1.4.34 | 08/10/26 | Updated planned expansion of C1 trading hours for select equity options to TBD. |