Introduction

London Stock Exchange Group (LSEG) operates some of the most critical market infrastructure in global capital markets. One such platform is Autex Trade Route (ATR), a cornerstone of global FIX order routing connectivity that links buy-side and sell-side firms across regions. With trading volumes rising, volatility returning, and infrastructure expectations changing, LSEG set out to modernise ATR without disrupting the thousands of firms that rely on it daily. To achieve this, LSEG partnered with Rapid Addition to underpin a large-scale, low-risk transformation of the platform on Microsoft Azure.

Problem

ATR is one of the world’s largest FIX order routing and IOI networks, connecting over 1,000 buy-side firms to more than 600 brokers, with north of 5,000 individual FIX connections and processing around 4 billion shares per day. While highly successful, the platform faced challenges common to long-established trading infrastructure:

• Legacy architecture that limited scalability and agility
• Growing operational risk as volumes, data and regulatory expectations increased
• The need to modernise infrastructure without downtime or client-side changes
• Pressure to reduce time to market and infrastructure costs while maintaining resilience

Compounding the challenge, ATR operates on a near 24/6 basis to support global markets, including Middle East trading, leaving only a very small maintenance window for upgrades or changes.

Given ATR’s global, near-continuous trading operation, any disruption would have a significant reputational and commercial impact. LSEG needed a solution that could offer controlled migration, preserve existing workflows and FIX connectivity, deliver cloud-scale resilience, and ultimately provide a single, strategic platform for LSEG’s trading products.

Solution

LSEG selected Rapid Addition’s electronic trading technology as the core platform to re-architect ATR for the cloud. Rapid Addition’s protocol agnostic, modular workflow platform enabled ATR to be redesigned to run on Microsoft Azure while fully supporting existing client connections, routing logic and FIX protocol versions.

Key elements of the solution included:

• A cloud deployment of ATR on Azure, designed for high availability, elasticity and global scale
• Rapid Addition’s high-performance FIX technology and flexible workflow framework to replicate and enhance existing order routing logic
• Real-time observability and monitoring to provide deep operational insight across global trading flows
• A phased migration approach that eliminated the need for a “big bang” cutover and avoided any trading disruption
• Integrated change management process enabling seamless roll-back/roll-forward

This architecture allowed LSEG to modernise the platform end-to-end while maintaining continuous service for the global trading community.

Results

The success of the transformation was quickly demonstrated under real-world conditions. Shortly after going live, ATR experienced a 400% surge in trading volumes during a period of heightened market volatility. The platform scaled seamlessly, with zero outages or service degradation.

Key outcomes included:

• Proven resilience and scalability under extreme market stress
• Faster deployment of new FIX hubs, reducing time to market from months to weeks
• Lower infrastructure and operational costs through cloud deployment
• Improved operational visibility and confidence through real-time monitoring
• A future-ready platform capable of supporting innovation and growth
• A notable example of the new agility was the launch of a new ATR FIX hub in Singapore in just four weeks, highlighting the combined power of Azure and Rapid Addition’s modular architecture.

Next Steps

With the modernised ATR platform in place, LSEG is well-positioned to build on this foundation. Next steps include expanding global connectivity and unlocking deeper analytics from the billions of daily FIX messages flowing through the platform.

LSEG has confirmed a long-term partnership with Rapid Addition around the addition of more features to the ATR network and connections from other networks. In addition to that, the exchange is running other expensive legacy networks that they want to modernise and integrate into an automated workflow.

More broadly, the Aa TR transformation provides LSEG with a repeatable blueprint for modernising other critical market infrastructure. For the wider capital markets industry, it demonstrates how partnering with the right strategic technology provider can de-risk legacy modernisation and deliver resilience, scale and innovation without compromising day-to-day trading operations.