Skip to main content

Concept

The introduction of an all-to-all (A2A) trading protocol into the request-for-quote (RFQ) ecosystem represents a fundamental architectural redesign of over-the-counter (OTC) market structures. It is a calculated shift from a segmented, dealer-centric liquidity model to a networked, multilateral system. This evolution directly addresses the inherent limitations of bilateral negotiations, where a client’s access to competitive pricing is structurally constrained by their established dealer relationships. The traditional RFQ process, a robust mechanism for sourcing liquidity in less liquid markets like corporate bonds, operates on a hub-and-spoke model.

The client (the liquidity taker) sits at the center, broadcasting a request to a select, permissioned group of dealers who then compete to provide the best price. The system’s efficiency is a direct function of the number and aggressiveness of the responding dealers in that client’s network.

An A2A protocol dismantles this permissioned structure. It transforms the RFQ from a series of private, bilateral conversations into a multilateral auction open to a vastly expanded set of potential liquidity providers. This set now includes traditional dealers, regional banks, specialized electronic market makers, and, most significantly, other institutional investors (the buy-side). In this framework, a buy-side institution can be both a liquidity taker and a liquidity provider, sometimes within the same instrument on the same day.

This dual capacity is the core systemic alteration. It introduces a new, dynamic source of liquidity that was previously latent within the market ▴ the resting inventory of other asset managers. The A2A protocol, therefore, functions as a system-level resource aggregator, unlocking this latent liquidity and making it accessible to the entire network.

The all-to-all protocol re-architects the RFQ process from a closed, bilateral negotiation into an open, multilateral auction, fundamentally expanding the pool of accessible liquidity.

This architectural change has profound implications for the very nature of negotiation. In the traditional model, negotiation is relationship-driven and characterized by information asymmetry. A dealer’s quote is influenced by their inventory, their perception of the client’s urgency, and their assessment of the client’s access to alternative quotes. The A2A model introduces a layer of competitive pressure that is more systemic and anonymous.

When an RFQ is broadcast into an A2A network, it is not just the originally targeted dealers who may respond. Other asset managers holding the bond can see the request and may offer a better price than the dealers, seeking to exit a position without incurring the full bid-ask spread. This potential for an unexpected, highly competitive response from a non-dealer forces all participants, especially the traditional dealers, to tighten their pricing. The negotiation dynamic shifts from a calculation of “what can I price this at for this specific client?” to “what must I price this at to win against the entire network, including other investors?”.

This systemic competition directly benefits the RFQ initiator through improved price discovery and lower transaction costs. The introduction of A2A protocols has been a significant development in the electronification of corporate bond markets, with platforms like MarketAxess’s Open Trading and Tradeweb’s AllTrade leading this structural evolution. Research indicates that by 2020, A2A trading accounted for a notable 12% of investment-grade corporate bond volume, a significant increase from just 5% in 2017, underscoring its rapid adoption and impact.


Strategy

Integrating all-to-all (A2A) protocols into a trading strategy requires a deliberate recalibration of how an institution interacts with the market. It is a move from managing a series of distinct dealer relationships to navigating a complex, interconnected liquidity network. The strategic imperatives diverge for different market participants, but all are centered on adapting to a new information environment and a reconfigured competitive landscape. For the buy-side institution initiating the RFQ, the primary strategic shift is from optimizing counterparty selection to optimizing protocol selection.

Robust institutional-grade structures converge on a central, glowing bi-color orb. This visualizes an RFQ protocol's dynamic interface, representing the Principal's operational framework for high-fidelity execution and precise price discovery within digital asset market microstructure, enabling atomic settlement for block trades

Redefining Liquidity Sourcing

The traditional RFQ strategy was heavily dependent on pre-trade intelligence about which dealers were likely to be axed in a particular security. A portfolio manager’s edge was derived from knowing who to call. The A2A protocol supplements this with a powerful, anonymized liquidity discovery tool. The strategy here becomes a multi-step process.

  1. Initial Screening ▴ The first step is still the traditional, disclosed RFQ to a small group of trusted dealers. This maintains the relationship aspect, which remains valuable for market color and for executing extremely large or sensitive orders.
  2. Concurrent A2A Exposure ▴ Simultaneously, the RFQ is exposed to the anonymous A2A pool. This acts as a competitive backstop. The buy-side trader is now benchmarking their trusted dealers’ quotes not just against each other, but against a potentially vast and unseen pool of other participants.
  3. Dynamic Response Evaluation ▴ The strategic execution involves monitoring the responses from both channels. A highly competitive quote from the A2A pool can be used to pressure a relationship dealer to improve their price. Conversely, if the A2A pool provides no competitive responses, it validates the pricing from the dealer network.

This blended approach allows the buy-side to achieve the “best of both worlds” ▴ maintaining valuable dealer relationships while harnessing the competitive power of a broader network. Studies on the impact of A2A systems, like MarketAxess’s Open Trading, show that this competition measurably improves pricing for the initiator. The very presence of the A2A option forces all liquidity providers to assume there is another, better price available to the initiator, thus tightening the quotes they provide.

A sleek, circular, metallic-toned device features a central, highly reflective spherical element, symbolizing dynamic price discovery and implied volatility for Bitcoin options. This private quotation interface within a Prime RFQ platform enables high-fidelity execution of multi-leg spreads via RFQ protocols, minimizing information leakage and slippage

New Dynamics for Liquidity Providers

For traditional dealers, the strategy must evolve from being gatekeepers of liquidity to becoming highly efficient competitors within a larger pool. Their business model is directly challenged by the buy-side-to-buy-side (B2B) flow that A2A enables. A dealer’s strategy must now incorporate advanced algorithmic pricing engines that can respond to RFQs instantly and competitively.

The profit margin on any single trade may decrease due to the heightened competition, so profitability must be pursued through higher volumes and greater efficiency. Furthermore, dealers themselves can use the A2A network to source liquidity to fill a client’s order, effectively acting as an intermediary for the broader network.

A new category of participant, the non-bank or quasi-dealer liquidity provider, also emerges. These are often quantitative trading firms or specialized hedge funds that are not traditional bond dealers but have the technological infrastructure to make markets. Their strategy is purely quantitative. They leverage data and speed to respond to thousands of RFQs, aiming to capture a small spread on a massive volume of trades.

Their entry into the market is a direct consequence of the A2A architecture and adds another layer of intense competition. Research has shown that this new category of liquidity provider has become a significant component of A2A volume, sometimes exceeding the liquidity provided by other investors.

The strategic core of all-to-all trading is the shift from managing curated counterparty lists to orchestrating competition across a networked and diverse liquidity ecosystem.
A smooth, light-beige spherical module features a prominent black circular aperture with a vibrant blue internal glow. This represents a dedicated institutional grade sensor or intelligence layer for high-fidelity execution

How Does A2A Impact Information Leakage?

A critical strategic consideration in any RFQ negotiation is information leakage. Broadcasting a large order to the market can signal intent, leading to adverse price movements. The traditional RFQ model contains this risk by limiting the request to a small, trusted group of dealers. The A2A model, with its broader, anonymous dissemination, appears to heighten this risk.

However, the anonymity of the protocol provides a powerful counter-measure. While more participants see the request, they do not necessarily know who the initiator is. This anonymity can be a strategic advantage for institutions trading in sizes that are large enough to move markets but not so large as to be identifiable by their footprint alone. Surveys of buy-side traders indicate that while concerns about information leakage in electronic trading persist, the benefits of accessing a wider, anonymous pool of liquidity often outweigh the risks, particularly when compared to the potential for leakage in voice-based trading.

The table below outlines the strategic shifts for a buy-side trading desk when adopting an A2A RFQ protocol.

Strategic Framework Transformation Buy-Side Desk
Strategic Component Traditional RFQ Model All-to-All RFQ Model
Primary Goal Secure best price from a known set of dealers. Secure best price from the entire network, including dealers and other investors.
Liquidity Source Permissioned dealer network. Permissioned dealers plus an anonymous, multilateral network of all participants.
Key Skill Relationship management and counterparty knowledge. Protocol optimization and dynamic response analysis.
Information Control Contained within a small, disclosed group. High trust, but limited competition. Broader dissemination, but with initiator anonymity. Risk is managed via protocol features.
Benchmarking Quotes are benchmarked against other responding dealers in the trusted set. Quotes are benchmarked against the entire responding network, creating a more robust competitive benchmark.
Execution Tactic Sequential or simultaneous RFQ to a few dealers. Blended approach of disclosed RFQ to core dealers and concurrent anonymous RFQ to the A2A network.


Execution

The execution of trades within an all-to-all (A2A) RFQ environment is a function of technological integration, procedural discipline, and quantitative analysis. For an institutional trading desk, moving from a purely traditional RFQ process to one that incorporates an A2A protocol is a significant operational undertaking. It requires changes to the Order Management System (OMS) and Execution Management System (EMS), new workflows for traders, and a more sophisticated approach to Transaction Cost Analysis (TCA).

Textured institutional-grade platform presents RFQ inquiry disk amidst liquidity fragmentation. Singular price discovery point floats

The Operational Playbook an A2A Integration Guide

Successfully integrating an A2A protocol is a structured process. The following playbook outlines the critical steps for a buy-side institution.

  • System and Vendor Selection ▴ The first step is to ensure the institution’s EMS/OMS provider has robust integrations with the major A2A trading platforms (e.g. MarketAxess Open Trading, Tradeweb AllTrade, Bloomberg Bridge). The integration must support the seamless routing of RFQs to both disclosed dealers and the anonymous A2A pool. It must also be able to receive and correctly attribute responses from all sources in a unified interface.
  • Protocol Configuration ▴ The trading desk must establish clear, written guidelines for when and how to use the A2A protocol. This involves setting thresholds based on order size, security liquidity, and market conditions. For example, orders below a certain size (e.g. $1 million notional) might be automatically routed to the A2A network, while larger, less liquid blocks may require a more manual, relationship-based approach initially.
  • Pre-Trade Analytics Integration ▴ The execution workflow must begin with pre-trade analytics. Modern platforms provide data on the likely liquidity available for a specific bond in the A2A network. Traders must be trained to consult this data before initiating an RFQ to set realistic expectations and to decide on the optimal number of dealers to include in the disclosed portion of the request.
  • Post-Trade TCA Enhancement ▴ The TCA process must be upgraded to capture the unique benefits of the A2A protocol. It is insufficient to simply measure execution price against a benchmark like TRACE. The analysis must quantify the “price improvement” achieved through the A2A network. This means comparing the winning price to the best price offered by the disclosed dealer group. This metric becomes the key performance indicator for the A2A protocol’s effectiveness.
A sleek, illuminated object, symbolizing an advanced RFQ protocol or Execution Management System, precisely intersects two broad surfaces representing liquidity pools within market microstructure. Its glowing line indicates high-fidelity execution and atomic settlement of digital asset derivatives, ensuring best execution and capital efficiency

Quantitative Modeling and Data Analysis

The value of A2A trading is most clearly demonstrated through data. A rigorous quantitative approach is essential to validate its adoption and to refine its use over time. The table below presents a hypothetical analysis of RFQ responses for a single corporate bond trade, illustrating how TCA can be used to measure the impact of an A2A protocol.

RFQ Response Analysis ▴ $5M Trade in ABC 4.25% 2030 Corp Bond
Liquidity Provider Provider Type Channel Response Time (ms) Quoted Price (Buy) Price Improvement vs. Best Dealer
Dealer A Traditional Dealer Disclosed RFQ 1,500 99.50
Dealer B Traditional Dealer Disclosed RFQ 1,800 99.48 -0.02
Dealer C Traditional Dealer Disclosed RFQ 2,200 99.45 -0.05
Provider X Quasi-Dealer A2A (Anonymous) 350 99.51 +0.01
Provider Y Asset Manager A2A (Anonymous) 4,500 99.54 +0.04

In this scenario, the best price from the traditional, disclosed dealer network was 99.50. However, two anonymous responses were received through the A2A channel. The first, from a high-frequency quasi-dealer, offered a marginal improvement. The second, from another asset manager looking to sell the bond, offered a significant price improvement of 4 cents per $100 of face value.

For a $5 million trade, this translates to a cost saving of $2,000. This is the quantifiable value of the A2A protocol. The analysis also reveals other important dynamics. The response time from the quasi-dealer is extremely fast, reflecting its algorithmic nature.

The response from the other asset manager is slower, likely reflecting a more manual process, but ultimately provides the best price. This highlights the diversity of liquidity sources within the A2A network.

A disciplined execution framework transforms all-to-all trading from a novel concept into a quantifiable source of alpha through systematic cost reduction.
A sharp, metallic form with a precise aperture visually represents High-Fidelity Execution for Institutional Digital Asset Derivatives. This signifies optimal Price Discovery and minimal Slippage within RFQ protocols, navigating complex Market Microstructure

Predictive Scenario Analysis a Case Study

Consider a portfolio manager at a mid-sized asset management firm who needs to sell a $10 million block of a BBB-rated industrial bond. The bond is reasonably liquid but not a benchmark issue. In the traditional model, the trader would send an RFQ to 3-5 dealers they have a strong relationship with.

They might receive quotes around 98.75, with the best bid at 98.80. The trader’s decision is limited to this small set of responses.

Now, let’s replay this using an A2A-enabled workflow. The trader initiates a disclosed RFQ to the same 3-5 dealers but simultaneously allows the RFQ to be viewed by the anonymous A2A network. The dealer bids come in around the same level ▴ 98.75 to 98.80. However, two other participants in the A2A network respond.

A regional bank that the trader does not have a direct relationship with bids 98.82. A smaller hedge fund that has been building a position in the same bond and is seeking to add to it bids 98.85. The trader is now able to execute the entire $10 million block at 98.85, a price that was completely inaccessible through their traditional, permissioned network. This represents a savings of 5 cents per $100, or $5,000 on the trade. This scenario demonstrates the power of A2A to break down the informational silos that characterize traditional OTC markets and to create a more efficient, unified market for price discovery.

A sharp, translucent, green-tipped stylus extends from a metallic system, symbolizing high-fidelity execution for digital asset derivatives. It represents a private quotation mechanism within an institutional grade Prime RFQ, enabling optimal price discovery for block trades via RFQ protocols, ensuring capital efficiency and minimizing slippage

What Are the Technical Integration Requirements?

The technical architecture for A2A trading relies on standardized protocols, primarily the Financial Information eXchange (FIX) protocol. The integration requires specific enhancements to an institution’s trading systems.

  • FIX Protocol Extensions ▴ The firm’s FIX engine must support the specific tags and message types used by the A2A platforms for anonymous RFQs and responses. This is a non-trivial engineering effort that requires close collaboration with the platform vendors.
  • API Integration ▴ Modern platforms also offer REST APIs for accessing pre-trade analytics, liquidity scores, and other data. The EMS must be able to call these APIs to enrich the trader’s view of the market before an RFQ is sent.
  • Data Normalization ▴ The system must be able to ingest, normalize, and display data from multiple sources (disclosed dealers, anonymous A2A participants) in a single, coherent interface. This includes normalizing price conventions, timestamps, and provider identities (even if anonymized). This unified view is critical for enabling the trader to make the optimal execution decision quickly.

Ultimately, the execution of A2A trading is about building a system ▴ a combination of technology, procedure, and analytics ▴ that allows the trading desk to systematically and repeatedly access the deepest, most competitive pool of liquidity available for any given trade. It is the operational manifestation of the strategic shift toward a networked market structure.

Intersecting abstract geometric planes depict institutional grade RFQ protocols and market microstructure. Speckled surfaces reflect complex order book dynamics and implied volatility, while smooth planes represent high-fidelity execution channels and private quotation systems for digital asset derivatives within a Prime RFQ

References

  • McPartland, Kevin. “All-to-All Trading Takes Hold in Corporate Bonds.” Greenwich Associates, 2021.
  • Hendershott, Terrence, Dmitry Livdan, and Norman Schürhoff. “All-to-All Liquidity in Corporate Bonds.” Toulouse School of Economics, 2021.
  • Anaya, Pablo, et al. “All-to-All Trading in the U.S. Treasury Market.” Federal Reserve Bank of New York Economic Policy Review, vol. 31, no. 2, 2025.
  • Weill, Pierre-Olivier. “The Frictions in Over-the-Counter Markets.” Journal of Economic Literature, vol. 58, no. 3, 2020, pp. 694-734.
  • Lee, Spencer. “Lessons from credit ▴ Could all-to-all help Treasury markets?” WatersTechnology, 2022.
Curved, segmented surfaces in blue, beige, and teal, with a transparent cylindrical element against a dark background. This abstractly depicts volatility surfaces and market microstructure, facilitating high-fidelity execution via RFQ protocols for digital asset derivatives, enabling price discovery and revealing latent liquidity for institutional trading

Reflection

The integration of all-to-all trading protocols marks a significant evolution in the architecture of market access. The knowledge of its mechanics and strategic implications provides a distinct operational advantage. Yet, viewing it as a standalone tool is to miss the larger point. Its true potential is realized when it is integrated into a holistic operational framework ▴ a system where technology, data, and human expertise are fused to create a cohesive intelligence layer.

A transparent sphere on an inclined white plane represents a Digital Asset Derivative within an RFQ framework on a Prime RFQ. A teal liquidity pool and grey dark pool illustrate market microstructure for high-fidelity execution and price discovery, mitigating slippage and latency

Where Does This New Liquidity Come From?

The emergence of this protocol prompts a fundamental question for any institution ▴ is our current operational system designed to merely execute trades, or is it engineered to harvest alpha from the very structure of the market itself? The A2A model reveals liquidity that was always present but systematically inaccessible. It challenges us to consider what other latent opportunities might exist within the market’s architecture, waiting for the right protocol or analytical framework to unlock them. The system you build today defines the opportunities you will be capable of seeing tomorrow.

Engineered object with layered translucent discs and a clear dome encapsulating an opaque core. Symbolizing market microstructure for institutional digital asset derivatives, it represents a Principal's operational framework for high-fidelity execution via RFQ protocols, optimizing price discovery and capital efficiency within a Prime RFQ

Glossary

A teal sphere with gold bands, symbolizing a discrete digital asset derivative block trade, rests on a precision electronic trading platform. This illustrates granular market microstructure and high-fidelity execution within an RFQ protocol, driven by a Prime RFQ intelligence layer

Corporate Bonds

Meaning ▴ Corporate bonds represent debt securities issued by corporations to raise capital, promising fixed or floating interest payments and repayment of principal at maturity.
A central luminous frosted ellipsoid is pierced by two intersecting sharp, translucent blades. This visually represents block trade orchestration via RFQ protocols, demonstrating high-fidelity execution for multi-leg spread strategies

Traditional Rfq

Meaning ▴ A Traditional RFQ (Request for Quote) describes a manual or semi-electronic process where a buyer solicits price quotations for a financial instrument from a select group of dealers or liquidity providers.
A translucent teal layer overlays a textured, lighter gray curved surface, intersected by a dark, sleek diagonal bar. This visually represents the market microstructure for institutional digital asset derivatives, where RFQ protocols facilitate high-fidelity execution

Liquidity Provider

Meaning ▴ A Liquidity Provider (LP), within the crypto investing and trading ecosystem, is an entity or individual that facilitates market efficiency by continuously quoting both bid and ask prices for a specific cryptocurrency pair, thereby offering to buy and sell the asset.
Intersecting multi-asset liquidity channels with an embedded intelligence layer define this precision-engineered framework. It symbolizes advanced institutional digital asset RFQ protocols, visualizing sophisticated market microstructure for high-fidelity execution, mitigating counterparty risk and enabling atomic settlement across crypto derivatives

A2a Protocol

Meaning ▴ An A2A Protocol in the crypto Request for Quote (RFQ) and institutional trading context represents a defined set of communication rules facilitating direct machine-to-machine interaction between distinct software applications.
An abstract, angular, reflective structure intersects a dark sphere. This visualizes institutional digital asset derivatives and high-fidelity execution via RFQ protocols for block trade and private quotation

Rfq

Meaning ▴ A Request for Quote (RFQ), in the domain of institutional crypto trading, is a structured communication protocol enabling a prospective buyer or seller to solicit firm, executable price proposals for a specific quantity of a digital asset or derivative from one or more liquidity providers.
A polished, teal-hued digital asset derivative disc rests upon a robust, textured market infrastructure base, symbolizing high-fidelity execution and liquidity aggregation. Its reflective surface illustrates real-time price discovery and multi-leg options strategies, central to institutional RFQ protocols and principal trading frameworks

Price Discovery

Meaning ▴ Price Discovery, within the context of crypto investing and market microstructure, describes the continuous process by which the equilibrium price of a digital asset is determined through the collective interaction of buyers and sellers across various trading venues.
A precise metallic central hub with sharp, grey angular blades signifies high-fidelity execution and smart order routing. Intersecting transparent teal planes represent layered liquidity pools and multi-leg spread structures, illustrating complex market microstructure for efficient price discovery within institutional digital asset derivatives RFQ protocols

Corporate Bond

Meaning ▴ A Corporate Bond, in a traditional financial context, represents a debt instrument issued by a corporation to raise capital, promising to pay bondholders a specified rate of interest over a fixed period and to repay the principal amount at maturity.
A precision instrument probes a speckled surface, visualizing market microstructure and liquidity pool dynamics within a dark pool. This depicts RFQ protocol execution, emphasizing price discovery for digital asset derivatives

Disclosed Rfq

Meaning ▴ A Disclosed RFQ (Request for Quote) in the crypto institutional trading context refers to a negotiation protocol where the identity of the party requesting a quote is revealed to potential liquidity providers.
A sophisticated proprietary system module featuring precision-engineered components, symbolizing an institutional-grade Prime RFQ for digital asset derivatives. Its intricate design represents market microstructure analysis, RFQ protocol integration, and high-fidelity execution capabilities, optimizing liquidity aggregation and price discovery for block trades within a multi-leg spread environment

Quasi-Dealer

Meaning ▴ A Quasi-Dealer, in the context of institutional crypto markets, denotes an entity that performs functions analogous to a traditional financial dealer, such as providing market liquidity, facilitating trades, and managing inventory, but typically operates without formal dealer registration or licensing.
A multi-faceted geometric object with varied reflective surfaces rests on a dark, curved base. It embodies complex RFQ protocols and deep liquidity pool dynamics, representing advanced market microstructure for precise price discovery and high-fidelity execution of institutional digital asset derivatives, optimizing capital efficiency

Information Leakage

Meaning ▴ Information leakage, in the realm of crypto investing and institutional options trading, refers to the inadvertent or intentional disclosure of sensitive trading intent or order details to other market participants before or during trade execution.
Two sharp, intersecting blades, one white, one blue, represent precise RFQ protocols and high-fidelity execution within complex market microstructure. Behind them, translucent wavy forms signify dynamic liquidity pools, multi-leg spreads, and volatility surfaces

Electronic Trading

Meaning ▴ Electronic Trading signifies the comprehensive automation of financial transaction processes, leveraging advanced digital networks and computational systems to replace traditional manual or voice-based execution methods.
Abstract intersecting blades in varied textures depict institutional digital asset derivatives. These forms symbolize sophisticated RFQ protocol streams enabling multi-leg spread execution across aggregated liquidity

Trading Desk

Meaning ▴ A Trading Desk, within the institutional crypto investing and broader financial services sector, functions as a specialized operational unit dedicated to executing buy and sell orders for digital assets, derivatives, and other crypto-native instruments.
Interlocking modular components symbolize a unified Prime RFQ for institutional digital asset derivatives. Different colored sections represent distinct liquidity pools and RFQ protocols, enabling multi-leg spread execution

Transaction Cost Analysis

Meaning ▴ Transaction Cost Analysis (TCA), in the context of cryptocurrency trading, is the systematic process of quantifying and evaluating all explicit and implicit costs incurred during the execution of digital asset trades.
A cutaway view reveals the intricate core of an institutional-grade digital asset derivatives execution engine. The central price discovery aperture, flanked by pre-trade analytics layers, represents high-fidelity execution capabilities for multi-leg spread and private quotation via RFQ protocols for Bitcoin options

A2a Trading

Meaning ▴ Application-to-Application Trading denotes automated, direct electronic communication between distinct software systems for executing financial transactions.
Abstract layered forms visualize market microstructure, featuring overlapping circles as liquidity pools and order book dynamics. A prominent diagonal band signifies RFQ protocol pathways, enabling high-fidelity execution and price discovery for institutional digital asset derivatives, hinting at dark liquidity and capital efficiency

Fix Protocol

Meaning ▴ The Financial Information eXchange (FIX) Protocol is a widely adopted industry standard for electronic communication of financial transactions, including orders, quotes, and trade executions.
A precise, metallic central mechanism with radiating blades on a dark background represents an Institutional Grade Crypto Derivatives OS. It signifies high-fidelity execution for multi-leg spreads via RFQ protocols, optimizing market microstructure for price discovery and capital efficiency

All-To-All Trading

Meaning ▴ All-to-All Trading signifies a market structure where any eligible participant can directly interact with any other participant, whether as a liquidity provider or a taker, within a unified or highly interconnected trading environment.