Alt capital sustainability hinges on modeling, transparency, careful product sequencing: GC’s Rousseau

As alternative capital continues to integrate further into the global reinsurance market, in order for this to be truly sustainable the sector must prioritise better modeling, greater transparency and careful sequencing of product development so that capital can be deployed where it strengthens resilience, according to Laurent Rousseau of Guy Carpenter.

Rousseau’s comments come as Guy Carpenter has recently published a new report that examines the accelerating integration of alternative capital into the global reinsurance market and the implications for capacity, pricing, and market structure.

According to Guy Carpenter’s report, alternative capital now represents nearly 20% of the estimated US $660 billion in global reinsurance capital, a solid increase from 13% in 2013.

Nonetheless, as alternative capital continues to grow within the reinsurance sector, Guy Carpenter’s report highlights five structural frictions in the convergence of financial capital and the re/insurance industry that require consideration.

These frictions are: limitations in modeling, risks associated with trapped collateral/liquidity, a softening pricing cycle due to increased capacity, cultural disparities between capital markets and traditional reinsurance, and an increasing complexity/opacity in ultimate risk allocation.

Laurent Rousseau, CEO of Global Capital & Advisory and EMEA, Guy Carpenter, commented: “Over the past two decades, we have watched what was once a niche adjunct to reinsurance become a fundamental pillar of the market.

“That convergence is not merely about adding supply; it is reshaping the industry’s economics and identity as reinsurers become originators, structurers, and distributors of risk.”

He continued: “If this redesign is to be sustainable, the sector must prioritize better modeling, greater transparency around who ultimately bears losses, and careful sequencing of product development so that capital can be deployed where it truly strengthens resilience rather than amplifies systemic fragility.”

Meanwhile, Guy Carpenter’s report also highlights how public catastrophe bond issuance continues to reach record levels as more players continue to utilise the insurance-linked securities (ILS) market.

“Public catastrophe bond issuance reached about US$25 billion in 2025, bringing outstanding 144A cat bonds to roughly US$58 billion. When combined with sidecars and collateralized reinsurance, alternative reinsurance capital exceeded US$123 billion in 2025,” Guy Carpenter said.

Data tracked by Artemis shows that total issuance across Rule 144A and private cat bond transactions reached over $25.6 billion in 2025, which beat the previous record of just under $17.7 billion set a year earlier in 2024 by a staggering 45%.

Guy Carpenter further observed how the financial market’s expansion began with demand shocks from major catastrophes but has been sustained by a supply shock since 2022, which has seen higher interest rates and the investment appeal of insurance float attract pension funds, sovereign wealth funds and large alternative managers.

The broker also emphasises that reinsurers are progressively taking on the roles of originators and structurers, aligning risk tranches with investor appetites and generating structuring fees alongside underwriting margins, which heavily indicates a transition towards a more capital-markets-oriented economic model.

And lastly, Guy Carpenter also highlights how digital infrastructure and data center risks signify a potentially substantial new market opportunity. However, the broker stresses that the development of modellability, diversification, and standardised primary insurance products is essential before ILS and sidecars can expand into this space.