Elementum Advisors grows ILS AUM to $3.8bn, despite White Mountains investment declining

Elementum Advisors, LLC, an alternative investment manager that specialises in collateralized natural catastrophe reinsurance, entered 2026 with its assets under management increased to $3.8 billion, despite stakeholder White Mountains having reduced its investment in the Elementum ILS funds again.

The assets under management (AUM) headline figure increased by $100 million over the course of 2025, from $3.7 billion at January 1st last year to the new $3.8 billion figure, estimated at Jan 1st 2026.

While not an overly significant increase in the headline figure, we understand Elementum Advisors entered the new year with deployable capital having risen by more than the headline suggests, like many other ILS managers.

Notably though, while stakeholder White Mountains maintains its ownership interest in Elementum Advisors at a reported 26.6%, a limited partnership interest in the ILS manager it first took in 2019, the stakeholders investment into the Elementum ILS funds has been declining over time and dipped further in 2025.

Back on December 31st 2023, White Mountains had $161 million invested in ILS funds managed by Elementum.

The ILS investments declined over the next year, to $74 million as of December 31st 2024.

Then, in the last year, the ILS fund investments in Elementum Advisors managed strategies dipped further to $50 million as of December 31st 2025.

White Mountains has reduced a number of its ILS style investments into reinsurance funds and strategies over the last year, for example it did not renew its stake in the Outrigger Re sidecar structure of Ark Insurance Holdings.

For Elementum Advisors though, the ILS manager has continued to increase its headline assets under management, despite the declining investment from stakeholder White Mountains.

This shows Elementum has successfully been raising capital from third-party investors, to more than replace the shrinking of White Mountains ILS fund investment in its strategies.

One example we reported last October was that the Government Superannuation Fund Authority of New Zealand added insurance-linked securities (ILS) specialist Elementum Advisors to its roster of ILS managers in 2025.

Last year, Elementum expanded its range of ILS funds as well, expanding its collateralized reinsurance fund range and also adding a new catastrophe bond fund strategy.

Elementum Advisors is just one of the specialist managers of catastrophe bond and ILS funds listed in our Insurance Linked Securities (ILS) Investment Managers & Funds Directory.