Siena Capital Group, LLC, a private investment office with a focus on special situations and that counts former Gallagher Securities trading and distribution specialist Jack Stone as a Partner, is targeting the catastrophe bond and insurance-linked securities (ILS) market with a plan to launch a daily pricing platform later this year.
Siena Capital Group was founded in April 2025 by Luke Meehan (General Partner) and Jack Stone (Partner).
Stone most recently worked at Gallagher Securities where he syndicated primary cat bond transactions and led the firm’s catastrophe bond secondary market trading desk, which, according to sources, was a particularly active trading desk at the time of Stone’s departure.
As a result, Stone has deep expertise in the analysis for and delivery of catastrophe bond marks and pricing sheets, and this is one of the first targets for Siena Capital Group, as it looks to modernise market infrastructure in insurance-linked securities (ILS).
Artemis spoke with Stone to get a deeper understanding of the new company’s plans and what the cat bond market can expect from Siena Capital as it develops its technology and platform.
The key take-away is that this ambitious start-up wants to construct enterprise grade pricing infrastructure for the insurance-linked securities (ILS) marketplace.
Stone began by explaining the problem Siena Capital aims to solve, “Despite the growth of the catastrophe bond market, institutional infrastructure has not kept pace. Daily pricing is, for all practical purposes, non-existent. Broker sheets are still distributed via Excel, assumptions are often opaque, and managers and LPs are left without a consistent framework to validate NAV, compare portfolios, or defend valuations to auditors. It’s a system that creates friction at precisely the moment this asset class should be scaling with confidence.
“We’re changing that. In Q4 2025, Siena Capital Group will launch a fully web-based, audit-defensible catastrophe bond pricing platform—built entirely in-house, from the ground up. We use no third-party applications, no external data vendors, and no outsourced tooling. Every line of logic, every data pathway, and every pricing function is purpose-built to serve one mission: to deliver the first institutional-grade pricing utility for the ILS market.”
Stone went on to say, “This is not just another broker sheet. And we are not an ILS fund. We’re building what we believe will become the spine of cat pricing – a system that can support multiple scientifically and market-supported views of risk, track every mark over time, and provide full transparency into how and why valuations move.
“While many in the market are focused on ‘matching capital to risk,’ we’ve chosen to move upstream, starting with a much harder question: how do you price risk in a way that’s consistent, transparent, and defensible? Without that, any downstream structure—no matter how flashy—lacks real integrity.”
Stone went on to explain that Siena Capital aims to address these issues it sees in a way that is aligned with the needs of catastrophe bond market constituents.
“We’re not interested in building a demo-driven startup with a splashy UI and vague promises. Without being too forward, I fear that much of the recent innovation in this space appears designed to impress venture capital firms, not actual ILS managers or LPs,” he told us. “We will deliver a platform that’s serious, institutional-grade, and deeply useful to the professionals already operating in this market. The interface and functionality will be modeled on the best-in-class financial systems that managers and allocators already trust.”
The company sees this initial platform offering as core to its strategy but hopes to move further into the insurance-linked securities (ILS) and reinsurance investments space, by providing greater transparency to the sector in the hope of fostering a more liquid marketplace.
“We’re starting with cat bonds, but there’s no reason to stop there,” Stone said. “The infrastructure we’re building is designed to expand into collateralized re, sidecars, traditional reinsurance, ILWs, and ultimately any structure where investors need to understand and trust the reference point for risk.”
Hiring is already underway, and Stone provided some hints into what the market can expect to see in time.
“Our CTO brings more than a decade of experience leading engineering at one of the world’s largest financial technology platforms, with deep background in data architecture at global financial institutions. He will be leading a pod of talented engineers this summer as we run the sprint to Q4 launch,” Stone further stated. “He’s helping us build with the discipline and scale this market has long deserved, but has never had. When we formally introduce our team this summer, I believe our clients will immediately understand how seriously Siena Capital has invested in delivering them a best-in-class product. We cannot emphasise enough that we are sparing no expense to do this the right way, from the ground up.”
Adding that, “Importantly, we’re doing this without the interference of outside venture capital or the drag of corporate bureaucracy. This summer, we’re quietly testing the marks with a small group of long-standing ILS managers and allocators–investors who’ve been hungry for better pricing, willing to pay for it, and supportive of this initiative from the very beginning. Their feedback is directly shaping our rollout. Over the next 2-3 years, I am optimistic that managers who adopt our infrastructure will realise tremendous operational efficiencies, which is especially critical as some LPs become more fee-sensitive.”
Siena Capital has long-term ambitions to write primary personal and commercial lines insurance, which is why they have made their first investment with the aim of marshalling more LP capital to existing ILS managers.
Stone told Artemis, “Our ultimate goal is simple: to lower the cost of insurance for everybody.
“Looking ahead to the next five years, my business partner and I expect to personally capitalise U.S. admitted and E&S balance sheets, underwrite along the same infrastructure spine, and cede slices of risk into the ILS market, monitoring everything in real-time, at policy-level granularity.
“This is the future of the (re)insurance industry: where capital and risk meet transparently, dynamically, and without layers of inefficiency. So, of course we are interested in connecting risk to capital, just not yet.
“Getting tech and infrastructure right is the challenging part, and it’s the critical first step. Hiring top tier underwriting talent and managing the capital are the easy and fun parts, respectively.”
