The Challenge: Realistic Testing for Complex, Fragmented Markets
Modern trading teams — including developers, quants, and traders — face significant barriers when it comes to testing, validating, and improving trading strategies:
- Lack of Realism: Most available simulators focus on simplified, single-asset scenarios or overlook key market dynamics like fragmented liquidity, auction phases, or market structure complexity.
- Data Limitations: Historical market data is expensive, incomplete, or difficult to access — yet essential for accurate backtesting and stress testing.
- Rigid Tools: Proprietary platforms are often closed systems with limited extensibility, lacking full lifecycle order handling, or integration with real-world trading workflows.
- Inability to Replicate Market Events: Simulating high-volatility events, price swings, or extreme market conditions is rarely possible with existing solutions.
These limitations increase operational risk, slow down development cycles, and hinder innovation — particularly in fast-moving areas like algorithmic and automated trading.
Our Experience: The Need for Multi-Asset, Real-World Simulation #
At Quod Financial, we develop advanced trading infrastructure for clients operating across fragmented, multi-venue environments. To properly test execution strategies, we required:
- A simulator capable of replicating diverse, real-world market scenarios across multiple asset classes.
- The ability to replay historical market data and generate synthetic orders to mimic genuine price discovery and liquidity behavior.
- A scalable, developer-friendly tool that integrates seamlessly into existing DevOps workflows.
- Support for modern trading protocols like FIX, alongside administrative control through accessible APIs.
We couldn’t find a tool that offered all this — so we built QuantReplay.
Introducing QuantReplay: Open Source Market Simulation #
QuantReplay is an open-source, multi-asset market simulator designed to meet the demands of today’s trading technology landscape. It provides:
- Multi-Asset Support: Simulate order-driven markets including Equities, FX, Futures, Derivatives, and Digital Assets.
- Market Listings & Phases: Configure multiple venues with standard symbology, market rules, and distinct phases such as continuous trading and auctions.
- Matching Engine: Industry-standard price/time priority order book logic with full order lifecycle handling and configurable order types.
- Historical Data Playback: Replay multi-level market data from files or databases for realistic backtesting.
- Synthetic Order Generation: Inject realistic, pseudo-random orders to emulate live market activity, with control over price ranges, volumes, and update rates.
- Interfaces Built for Developers:
➡ FIX API for order flow and market data publishing.
➡ REST API for remote configuration and system monitoring. - Lightweight, Scalable Deployment: Runs as a single native process per venue, fully dockerized for easy deployment to any environment.
- Recovery Options: Save system state for seamless restart and high-availability testing.
Why Open Source? Community-Driven Innovation #
QuantReplay is designed with an open, community-first approach — extensible, adaptable, and welcoming contributions. The roadmap includes:
- Additional Market Phases: Support for auctions, trade-at-last phases, and more.
- Multi-Listed Instruments: Synchronize price behavior across multiple listings of the same asset.
- Real-Time Data Playback: Feed live market data through QuantReplay for real-time, tradeable simulations.
- Extreme Market Events: Schedule volatility spikes, market crashes, and stress scenarios.
- Client Simulation Mode: Run QuantReplay as a market participant to inject realistic order flows into third-party trading platforms.
- AI-Driven Market Simulation: Leverage Generative Adversarial Networks (GANs) for more advanced, real-time order generation that mirrors complex market dynamics.
- Quote-Driven Market Support: Extend to bilateral pricing workflows like FX streaming, RFQ (Request For Quote) models, and fixed income simulations.
The Outcome: Realistic Testing, Faster Innovation #
Our goal is to empower developers, quants, and trading teams to build, test, and deploy faster — with confidence.
- Validate execution strategies across fragmented, high-volume, or extreme market conditions.
- Build confidence in trading system performance before deploying to production.
- Reduce operational and regulatory risks by stress-testing under realistic scenarios.
- Accelerate time-to-market for algorithmic strategies with streamlined, developer-friendly tools.
QuantReplay is free, open source, and built for the community.
Contributions, feedback, and feature requests are welcome — together, we can make market simulation more accessible, realistic, and powerful for all.
#
FAQ #
- What is QuantReplay?
QuantReplay is an open-source, multi-asset market simulator designed to meet the demands of today’s trading technology landscape. It provides:
- Multi-Asset Support: Simulate order-driven markets including Equities, FX, Futures, Derivatives, and Digital Assets.
- Market Listings & Phases: Configure multiple venues with standard symbology, market rules, and distinct phases such as continuous trading and auctions.
- Matching Engine: Industry-standard price/time priority order book logic with full order lifecycle handling and configurable order types.
- Historical Data Playback: Replay multi-level market data from files or databases for realistic backtesting.
- Synthetic Order Generation: Inject realistic, pseudo-random orders to emulate live market activity, with control over price ranges, volumes, and update rates.
- Interfaces Built for Developers:
- FIX API for order flow and market data publishing.
- REST API for remote configuration and system monitoring.
- Lightweight, Scalable Deployment: Runs as a single native process per venue, fully dockerized for easy deployment to any environment.
- Recovery Options: Save system state for seamless restart and high-availability testing.
- How to get started with QuantReplay?
Visit: github.com/QuodFinancial/QuantReplay or Go through the detailed documentation to learn more .
- Is QuantReplay free to use?
QuantReplay is free, open source, and built for the community. Built by Quod Financial — a global leader in trading technology.
- Is QuantReplay open-source?
QuantReplay is designed with an open, community-first approach — extensible, adaptable, and welcoming contributions. The roadmap includes:
- Additional Market Phases: Support for auctions, trade-at-last phases, and more.
- Multi-Listed-Instruments: Synchronize price behavior across multiple listings of the same asset.
- Extreme Market Events: Schedule volatility spikes, market crashes, and stress scenarios.
- Client Simulation Mode: Run QuantReplay as a market participant to inject realistic order flows into third-party trading platforms.
- AI-Driven Market Simulation: Leverage Generative Adversarial Networks (GANs) for more advanced, real-time order generation that mirrors complex market dynamics.
- Quote-Driven Market Support: Extend to bilateral pricing workflows like FX streaming, RFQ (Request For Quote) models, and fixed income simulations.
- Why is QuantReplay free and open-source?
Quod Financial — a global leader in trading technology; believes the financial industry needs innovation —but innovation requires access.
- We want to democratize testing and automation. Most firms lack the tools or budgets to simulate real-world trading conditions. QuantReplay removes that barrier.
- We invite global collaboration. Developers and traders alike can build on QuantReplay, improving it for everyone.
- We're here to change the game. Quod Financial is committed to reshaping how trading tech is built and shared. Open-source is our way of giving back to the industry we serve.