FIX Trading Community Publishes Industry FAQ for 24-Hour Trading

The FIX Trading Community released its 24-Hour Markets Industry FAQ on 22 October 2026, a practitioner-built guide for firms adapting trading, connectivity and post-trade workflows to extended-hours and continuous trading sessions. The document is available now at fixtrading.org/packages/24hr-trading-faqs/.

The FAQ lands as exchanges, trading venues and market participants continue to explore longer sessions. Rather than proposing new standards, it maps how existing FIX data fields — the tagged message dictionary underpinning electronic order flow between buy-side and sell-side systems — can support 24-hour models while promoting consistent usage across the industry.

What does the FAQ actually cover?

The guide addresses the operational questions firms face as sessions extend. Key topics include:

• Trading sessions and sub-session flagging
• Trade date considerations
• Order management
• Post-trade processing
• Clearing implications
• Operational resilience

The thread running through each topic is reconciliation. Extended sessions dissolve the boundary conditions that operations teams have relied on to close books, match fills and allocate trades.

Enrico Cacciatore, Co-Chair of the FIX 24-Hour Markets Working Group and Co-Founder and Chief Product & Strategy Officer of CalcGuard Technologies, said: "Once the session never closes, basic questions like which trade date a fill belongs to, or which session it printed in, become where reconciliation breaks."

His prescription is deliberately conservative. "Most of the answers already exist in FIX. This FAQ shows firms how to use the fields they already have consistently, before every venue invents its own convention," Cacciatore said. That framing positions the FAQ as a fragmentation-prevention tool: absent a common convention, venues rolling out overnight sessions individually could impose divergent trade-date and session-identifier rules, multiplying integration work for brokers, asset managers and their vendors.

Who wrote it, and why now?

The FIX 24-Hour Markets Working Group, co-chaired by Cacciatore and John Greenan, developed the document from practitioner input rather than vendor marketing. Greenan, who serves as Head, Technologies at Aquis Technologies, framed the scope in operational terms.

"Extended-hours trading impacts far more than matching engines and order books. It touches everything from trade processing and risk controls to client workflows and market operations. This FAQ provides a common framework that firms can use as they assess and implement longer trading hours," Greenan said.

Jim Kaye, Executive Director of FIX Trading Community, tied the publication to demand from member firms. "The industry has been looking for a clear resource on this topic," Kaye said. "This FAQ document reflects the expertise of market participants from across the ecosystem and demonstrates how established FIX standards can help the industry adapt to new trading models without reinventing the wheel."

What does this change for desks and technology teams?

Nothing is mandated. The FAQ is guidance, not a rule, and carries no compliance deadline. Its practical value is as a reference baseline: firms reviewing order-management systems, FIX engines, reconciliation platforms and clearing arrangements for extended hours can test their designs against the working group's recommended field usage instead of deriving conventions from scratch.

For technology planners, the sub-session flagging and trade-date guidance touches the highest-risk seams — breaks between execution platforms, middle office and clearing — precisely where overnight sessions remove the natural end-of-day checkpoint. The document's emphasis on operational resilience signals that the working group treats staffing, monitoring and failover during historically quiet hours as part of the same problem set.

FIX Trading Community has not announced a follow-up standardization effort tied to the FAQ, but the working group's stated aim — consistent field usage before venue-level conventions diverge — implies future revisions as more venues publish their own extended-hours specifications.