The reinsurance sidecar market is projected for ongoing expansion, largely fueled by significant momentum within casualty sidecar structures. This insight comes from rating agency AM Best, which also emphasizes the potential for future growth in the wider collateralized reinsurance domain, attributing this to increased adaptability in structural design, analytical modeling, and risk categories.
Expanding Horizons for Casualty Sidecars
The casualty sidecar market, a pivotal component of the insurance-linked securities (ILS) sector, has experienced remarkable growth in recent years. AM Best estimates the current size of the overall sidecar market to be between $17 billion and $19 billion. Historically, property catastrophe risks dominated sidecar capacity, providing essential support to reinsurers during periods of market hardening. However, with the softening of the property catastrophe market and declining pricing, AM Best anticipates a deceleration in the growth of property catastrophe sidecars in the near future, as potential returns for ILS investors diminish. Conversely, casualty sidecars are expected to witness continued growth, partly due to the extended collateral holding periods, which offer an additional investment income component. Nevertheless, returns in this segment remain contingent on factors such as underwriting pricing, reserve development, liability duration, and asset-liability liquidity, underscoring that higher investment yields do not negate the need for accurate risk pricing. The appetite for US casualty risk varies among capacity providers; some are drawn to the insurance float and improved pricing, while others remain cautious given the challenging loss severity trends. Despite these concerns, some ILS capacity providers are increasingly capitalizing sidecars to gain exposure to casualty risk, a trend that accelerated throughout 2026. Notable examples include QBE Re's sponsorship of the $550 million George Street Re casualty sidecar and Everest Group's launch of Annapurna Re Ltd., aiming for $600 million in third-party capital.
While the casualty sidecar market's overall capital volume is still modest compared to the broader reinsurance market, AM Best projects substantial future growth. As this segment matures, it could eventually exert downward pressure on casualty reinsurance pricing during renewal cycles. Beyond sidecars, AM Best's report assesses the broader collateralized reinsurance market at an estimated $37 billion to $41 billion. Although this segment has not mirrored the rapid growth seen in catastrophe bonds and sidecars recently, ILS managers believe it holds significant future growth potential due to enhanced flexibility in its structure, modeling techniques, and the range of perils it covers. This increased flexibility is particularly crucial given that the catastrophe bond market remains heavily concentrated on US wind risk, suggesting a greater opportunity for peril diversification within the private collateralized reinsurance market. This strategic shift towards more flexible and diversified collateralized reinsurance offerings is a key trend to watch in the evolving insurance-linked securities landscape.
