Understanding Cboe’s U.S. Equities Exchanges: BZX, BYX, EDGX, and EDGA
Cboe is currently one of the largest U.S. Equities market operators, providing a robust infrastructure for trading National Market System (NMS) securities. By operating four distinct exchanges—BZX, BYX, EDGX, and EDGA—Cboe allows market participants to tailor their execution strategies based on specific liquidity needs, pricing models, and order flow preferences.
The Four Cboe Equities Exchanges
Whereas all four Cboe exchanges offer trading in all NMS securities, each maintains a unique order book and an independent fee schedule to attract different types of order flow. Understanding the differentiators between these platforms is essential for optimizing trading strategies.
Cboe BZX Exchange (Code Z)
The BZX Exchange focuses on hidden price improvement. It operates under a traditional “Maker-Taker” pricing model, which is a standard industry approach to incentivizing liquidity provision.
Cboe EDGX Exchange (Code K)
EDGX is designed to attract retail order flow and emphasizes attribution. Like BZX, it utilizes a traditional “Maker-Taker” pricing model to manage its liquidity and participants.
Cboe BYX Exchange (Code Y)
The BYX Exchange differentiates itself through retail price improvement. Unlike the other three exchanges, BYX employs a “Taker-Maker” model characterized by low fees and rebates.
Cboe EDGA Exchange (Code J)
EDGA focuses on routing without tiers. It follows the traditional “Maker-Taker” pricing model, providing a streamlined environment for specific execution strategies.
Comparative Overview of Cboe Exchanges
The following table summarizes the key differences between the four U.S. Equities platforms:
| Exchange | Exchange Code | Key Differentiator | Pricing Model |
|---|---|---|---|
| BZX | Z | Hidden Price Improvement | Maker-Taker |
| EDGX | K | Retail, Attribution | Maker-Taker |
| BYX | Y | Retail Price Improvement | Taker-Maker |
| EDGA | J | Routing, No Tiers | Maker-Taker |
Regulation and Oversight
The Cboe Exchanges are regulated by the Securities and Exchange Commission (SEC) as national securities exchanges. All four exchanges hold status as self-regulatory organizations (SROs).
Operational rules are strictly defined within each exchange’s Rulebook:
- Equities Trading: Rules for membership and trading across all four platforms are contained in Chapters I–XV of their respective Rulebooks.
- Options Trading: For BZX and EDGX, specific rules for options markets are detailed in Chapters XVI–XXIX, though Chapters I–XV remain applicable unless otherwise specified.
Liquidity and Order Routing
To ensure fast and efficient access to multiple pools of liquidity, Cboe provides a comprehensive Order Router. This system offers a variety of routing strategies, enabling members to execute trades across the different Cboe order books and other market venues with precision.
Key Takeaways
- Diverse Ecosystem: Cboe operates four U.S. Equities exchanges (BZX, BYX, EDGX, EDGA) to cater to different trading strategies.
- Pricing Variety: While most use a Maker-Taker model, BYX utilizes a Taker-Maker model with low fees and rebates.
- Regulatory Compliance: All platforms are SEC-regulated and function as SROs.
- Broad Access: All four exchanges provide trading capabilities for all NMS securities.
As market dynamics evolve, Cboe continues to expand its footprint. This growth is evident not only in the U.S. But also in its international operations, with Cboe Europe reporting record trading volumes in the first quarter of 2026.