Reinsurance: Insurance for Insurers

Introduction

Reinsurance is, at its simplest, insurance for insurance companies. When a primary insurer writes a policy that contains more risk than it wants to retain on its own balance sheet, it cedes a portion of the premium and risk to a reinsurer. The reinsurer absorbs part of the potential loss in exchange for a share of the premium. This risk-transfer mechanism is essential to the functioning of the global insurance market: without reinsurance, primary insurers could not write the catastrophe, liability, and specialty policies that the economy depends on.

The global reinsurance market generated approximately $470 billion in gross premiums in 2025, with dedicated reinsurance capital growing 9% year-over-year. Reinsurers earned approximately 17.6% return on equity in 2025, following 16.4% in 2024 and 21.9% in 2023, reflecting strong underwriting discipline and favorable pricing conditions. For FIG bankers, reinsurance is both a subsector to advise on (reinsurer M&A, capital markets transactions) and a mechanism to understand when analyzing P&C carrier risk profiles.

Reinsurance is structured in two primary forms:

Treaty Reinsurance

Treaty reinsurance is an automatic, pre-established agreement in which the reinsurer agrees to accept a defined class of risks from the primary insurer. Once the treaty is in place, every policy that falls within the treaty's scope is automatically ceded, with no individual risk evaluation. Treaty reinsurance accounts for approximately 70-75% of global reinsurance premiums.

Treaty structures include:

Quota share: the reinsurer assumes a fixed percentage of every policy in the class (e.g., 30% of all homeowners policies). Premiums and losses are shared proportionally. Quota share treaties are simple, provide capacity relief, and smooth earnings.

Surplus share: similar to quota share, but the cession percentage varies by policy based on the insurer's retention level. The insurer retains a fixed amount per policy and cedes the excess.

Excess of loss (XOL): the reinsurer pays losses that exceed a specified retention (attachment point) up to a coverage limit. The most common form for catastrophe protection: for example, "the reinsurer pays losses between $50 million and $200 million from any single catastrophe event." XOL treaties are non-proportional, meaning the reinsurer does not share proportionally in every loss but only pays when losses breach the attachment point.

Reinsurance

A risk-transfer arrangement in which a primary insurance company (the cedent) transfers a portion of its risk and premium to a reinsurance company (the reinsurer). Reinsurance serves four primary functions: (1) capital management, by reducing the net risk on the cedent's balance sheet, allowing it to write more business without holding proportionally more capital; (2) catastrophe protection, by limiting the cedent's exposure to large, infrequent events; (3) earnings stabilization, by smoothing the volatility of underwriting results; and (4) expertise transfer, as reinsurers bring global data and actuarial capabilities that inform pricing and risk selection. The cost of reinsurance (ceded premiums minus expected recoveries) is a significant expense for primary insurers, typically representing 15-30% of gross premiums.

Facultative Reinsurance

Facultative reinsurance involves the individual placement of specific risks. The primary insurer submits a particular policy or risk to reinsurers, who evaluate and price it independently. Facultative reinsurance is used for large, unusual, or complex risks that fall outside the scope of treaty arrangements (e.g., a single $500 million commercial property risk, a unique liability exposure, or a risk that exceeds treaty capacity).

Facultative business is growing faster than treaty in some markets (advancing at approximately 6.7% CAGR through 2030), driven by the increasing complexity of risks and the need for bespoke coverage structures.

The global reinsurance market is concentrated among a handful of large, well-capitalized players:

Munich Re's 80.6% reinsurance combined ratio in 2024 illustrates the strong pricing environment: the company earned nearly 20 cents of underwriting profit on every dollar of premium, a remarkable result driven by years of rate increases and disciplined catastrophe risk management.

Traditional reinsurance capacity is supplemented by alternative capital from institutional investors (pension funds, hedge funds, sovereign wealth funds) through insurance-linked securities:

Catastrophe bonds: capital markets instruments that transfer catastrophe risk to investors. If a specified catastrophe event occurs (defined by parametric triggers, industry loss indices, or modeled losses), investors lose their principal, which is used to pay claims. Cat bond issuance reached a record $17.4 billion in H1 2025, with total outstanding notional exceeding $58 billion (including cyber cat bonds). The market attracted 15 first-time sponsors in 2025.

Sidecars: special-purpose vehicles that co-invest alongside reinsurers in specific books of business, providing additional capacity in exchange for a share of underwriting profit.

Industry loss warranties (ILWs): contracts that pay based on industry-wide loss thresholds from specific events.

Total alternative/third-party capital in reinsurance reached an estimated $114 billion in 2025, up from $107 billion at year-end 2024. The growth of ILS has fundamentally changed the reinsurance market by introducing capital that is uncorrelated with financial markets, creating price competition with traditional reinsurers, and providing capacity that can be deployed quickly after catastrophe events.

Retrocession

Reinsurance purchased by reinsurers to manage their own risk. Just as a primary insurer cedes risk to a reinsurer, a reinsurer can cede a portion of its assumed risk to another reinsurer (the retrocessionaire). Retrocession is particularly important for managing peak catastrophe exposure: a reinsurer that writes property catastrophe treaties globally may have concentrated exposure to a single mega-event (a Category 5 hurricane making landfall in Florida, for example) and uses retrocession to cap its potential loss. The retrocession market is smaller and more specialized than the primary reinsurance market, with pricing that tends to be more volatile and capacity that contracts sharply after major loss events.

The convergence of traditional reinsurance with capital markets has created a hybrid market structure that is increasingly important for FIG advisory. Reinsurers now compete with ILS funds, sidecars, and cat bond sponsors for the same catastrophe risk, and the capital allocation decisions of institutional investors (pension funds committing capital to ILS strategies, hedge funds trading cat bonds) influence reinsurance pricing as much as traditional underwriting supply and demand. This convergence generates deal flow across structured transactions, capital markets issuance, and strategic M&A as traditional reinsurers seek to build or acquire alternative capital platforms.

Reinsurance sits at the intersection of risk management, capital markets, and global insurance economics. The sector's concentrated competitive structure, strong profitability during hard markets, and growing integration with alternative capital make it a distinctive and analytically rewarding area within the broader FIG landscape.