Digesting DyGIST: Preparing for the upcoming PRA insurance stress test

Author: Edwina Lister, Director - Risk Management, Moody's

With the U.K.'s Prudential Regulation Authority (PRA) planning its Dynamic General Insurance Stress Test (DyGIST) exercise in May 2026, thanks to all those who recently joined us at our City of London offices for a breakfast briefing to discuss response plans for the exercise.

At the briefing, we discussed the differences between DyGIST and previous General Insurance Stress Tests (GIST), such as in 2022, as for the first time, the PRA is now asking insurers to respond dynamically to a series of catastrophe event scenarios announced in real time. This will involve modeling the impact of cat event scenarios against their portfolios and providing both quantitative and qualitative responses under tight turnaround.

With Moody's part of the PRA's vendor communication channel, we are actively preparing to help our clients respond and to meet the demanding PRA timelines as closely as possible to our usual Moody's RMS Event Response process.

How Moody's will respond

As this is a dynamic stress test exercise, while we cannot predict exactly what events the PRA will announce, we shared our planned response framework at the briefing:

• Same-day response plans: As event details or updates are released by the PRA, we will publish our response plan and associated timelines on the same day.
• Stochastic event selections: For modeled peril regions, we will aim to provide event IDs that clients can use in our software.
• Adapted timelines: Recognizing the time pressure of the exercise, where feasible, we will adjust our processes to respond more quickly than usual.
• Non-modeled perils: If an event falls outside our standard modeling catalogue, we will strive to provide alternative support where possible.
• All updates published to Moody’s Support Center: Clients will be notified as products are released.

Peril-by-peril readiness

At the briefing, we walked through how our Event Response capabilities map to the types of events the DyGIST could include, from U.K. windstorms, floods, and earthquakes, through to cyber, terrorism, and casualty scenarios. For each event type, we outlined the expected deliverables and our realistic delivery timelines, including where the DyGIST format may require us to adapt our standard approach.

Preparing now will pay off in May

A significant part of the briefing focused on the practical steps clients can take today to be ready:

• Familiarize yourself with Moody’s RMS Event Response resources: Event Response help center, Risk Modeler help center, and Support Center articles are all available now.
• Prepare your exposure: Import your latest book of business, set up analysis templates, and determine optimal sample counts for high-definition (HD) model event response.
• Test your workflows: Run through the tools you'll use, whether on-premises or on the Moody’s Intelligent Risk Platform™, so there are no surprises during the exercise.
• Know where to go for support: Moody's Product Support team will be on hand throughout the exercise. Reach out via the Support Center or email RMSSupport@moodys.com, referencing PRA DyGIST.

A message from Mike Steel, General Manager, Moody's – Insurance Solutions

Mike Steel closed the briefing with two key messages that set the tone for how we are approaching this exercise:

1. We are here to support you: This is a partnership. We want to hear from our clients: your feedback, your ideas, your concerns. If there's something we can do better or differently to help you through DyGIST, we want to know. Our door is open.
2. Treat this as a learning exercise, not a tick-box exercise: The PRA has created an opportunity for the market to stress-test not just portfolios, but processes, decision-making, and communication under pressure.

The firms that approach DyGIST with a genuine willingness to learn — about their own readiness, their modeling assumptions, and their organizational response — will come out of it stronger and more resilient. That resilience benefits the entire market.

What's next?

We'll be sharing further guidance, resources, and thought leadership in the weeks ahead as we count down to May. If you have any questions about our DyGIST response plans or want to discuss your preparation, please reach out to your Moody's account representative.