Industry Loss Warranties (ILWs) Explained

An industry loss warranty (ILW) is a reinsurance contract that pays out when total insured losses across the whole industry from a catastrophe exceed a set threshold. The buyer's own losses barely matter. If a US hurricane causes $40 billion of industry losses and the contract attaches at $30 billion, it pays, whether the buyer lost a lot or a little.

ILWs are one of the four main instruments in the insurance-linked securities (ILS) market, alongside cat bonds, collateralized reinsurance, and sidecars. They are smaller and less visible than cat bonds because they are private contracts rather than securities, but they matter to cat bond investors for two reasons. They are priced off the same industry loss indices that many cat bonds use, and a growing share of retail-accessible ILS funds now holds them.

How an ILW Works

Every ILW is defined by four terms:

Peril and territory. For example, US named-storm hurricane, US earthquake, or European windstorm.
Industry loss trigger. The industry-wide insured loss that must be exceeded, such as $30 billion for a single US hurricane.
Limit. The amount the contract pays, for example $10 million.
Term. Usually 12 months, often aligned with a reinsurance renewal date.

The industry loss figure comes from an independent reporting agency rather than from the buyer. In the US that is PCS (Property Claim Services, part of Verisk). For Europe, Japan, Australia, and other regions, PERILS AG publishes the equivalent industry loss estimates.

Most ILWs also carry an ultimate net loss (UNL) condition: the buyer must show it suffered at least a nominal loss of its own from the same event. The UNL threshold is usually set low, so it rarely decides whether the contract pays. Its job is to give the buyer an insurable interest, which lets the contract be written and accounted for as reinsurance rather than as a pure derivative. Contracts written without the UNL condition exist too and are typically documented as swaps or other derivatives.

Binary versus pro-rata payouts

The classic ILW is binary. Once the industry loss passes the trigger, the full limit is paid. A $10 million ILW attaching at $30 billion pays nothing at $29.9 billion and $10 million at $30.1 billion.

Some contracts instead pay pro rata across a range. An ILW covering industry losses between $30 billion and $40 billion would pay 50% of its limit at $35 billion and 100% at $40 billion or more. That smooths out the cliff edge at the trigger, at the cost of a more complicated contract.

A worked example

The figures below are illustrative, not quotes from a real contract.

A regional insurer writes homeowners business in Florida and the Gulf Coast. It buys a $10 million binary ILW covering any single US hurricane that causes more than $30 billion of PCS-reported insured losses during the 12-month term, with a UNL condition of $1 million.

Scenario A: A hurricane hits the Gulf Coast and PCS reports $34 billion of industry losses. The insurer's own losses are $45 million. Both conditions are met, so the ILW pays $10 million.
Scenario B: A hurricane hits the Northeast and PCS reports $32 billion of industry losses, but the insurer has almost no exposure there and loses only $500,000. The industry trigger is met but the UNL condition is not, so the ILW pays nothing.
Scenario C: A hurricane hits the insurer's core market directly. Its own losses are $80 million, but the storm's industry total is $22 billion. The ILW pays nothing, even though the insurer took a large loss.

Scenario C is the buyer's basis risk: the gap between what the index measures and what the buyer actually loses. It is the main drawback of an ILW for the buyer, and it works the same way as basis risk in the parametric cat bonds discussed in How Hurricane Categories Affect Cat Bond Triggers.

ILWs Versus Industry-Loss Cat Bonds

An ILW and an industry-loss-triggered cat bond can reference the same PCS index for the same peril. The economic exposure is similar. The packaging is different.

	ILW	Industry-loss cat bond
Form	Private reinsurance contract or derivative	Rule 144A security issued by a special purpose vehicle (SPV)
Term	Usually 12 months	Usually 3–4 years
Payout	Often binary (all or nothing)	Usually pro rata across an attachment-to-exhaustion layer
Size	Typically smaller, sized to one buyer's need	Typically larger, sized for a broad investor base
Secondary trading	Rare; held to expiry	Traded over the counter between investors
Collateral	Collateralized if written by an ILS fund; otherwise backed by the seller's balance sheet	Fully collateralized in the SPV
Documentation	Short, standardized wording	Full offering circular, risk modeling report, and rating

The short documentation is what makes ILWs useful. A buyer can place an ILW in days, close to a renewal or ahead of hurricane season, without the months of preparation a cat bond needs. For more on how industry loss triggers compare with the alternatives, see Cat Bond Trigger Mechanisms Explained and Parametric vs Indemnity Cat Bond Triggers.

Who Buys and Who Sells

Buyers are mostly insurers and reinsurers looking for cheap, fast top-up protection. Reinsurers use ILWs heavily as retrocession, protection on their own reinsurance portfolios. A reinsurer that writes business across the whole US market has a loss profile that tends to track industry losses closely, so its basis risk on an ILW is lower than a regional insurer's.

Sellers include reinsurers, ILS funds, and hedge funds. For a capital provider, an ILW has a simple appeal: the risk depends only on how large an industry event gets, not on one company's underwriting or claims handling. That is easier to model and diligence than an indemnity contract.

How ILWs Are Priced

ILW pricing is quoted as rate on line (ROL): the premium divided by the limit. A $10 million ILW with a $1.5 million premium has a 15% rate on line.

The rate on line depends mainly on how likely the trigger is to be hit. A US hurricane ILW attaching at a lower industry loss, which is hit more often, costs more than one attaching at a much higher level. As with cat bonds, sellers charge a multiple of the modeled expected loss, and that multiple moves with the reinsurance cycle. After several years of firm pricing, ILW rates had been softening going into 2026.

Demand is seasonal. It peaks at the January 1 renewals and again at the June and July mid-year renewals, just before the North Atlantic hurricane season. SCOR Investment Partners reported "significant interest in purchasing ILW protection against US hurricane and US earthquake" at the 2026 mid-year renewals, with premium rates flat on average compared with the start of the year. Ahead of January 2026, the adviser to the City National Rochdale Select Strategies Fund said demand for ILW protection had been "significantly elevated," which it expected to "moderate recent price softening."

How Investors Get ILW Exposure

ILWs themselves are institutional products. The contracts are bilateral and usually run to $1 million or more, so individuals cannot buy them directly. Two US mutual funds registered under the Investment Company Act of 1940 now give investors indirect access:

Ambassador Fund (Embassy Asset Management). Launched in September 2021, the fund held about $967 million at the end of August 2026. At July 31, 2026, roughly 84% of its assets were in cat bonds and about 13% ($117.5 million) in privately negotiated ILW contracts, written in collateralized reinsurance form through its Consulate Re structure. It returned 11.61% in the year to October 31, 2025. See our news coverage: Ambassador fund hits ~$1bn in assets.
City National Rochdale Select Strategies Fund (CNRLX). The fund invests in ILWs and cat bonds, with the majority of its assets held through a Bermuda structure. It returned 11.27% net in the year to January 31, 2026, with $234.5 million in assets. See Artemis's report on the fund.

For an investor, the ILW sleeve changes the fund's risk in specific ways. ILWs cannot be sold before expiry, so that part of the portfolio is less liquid than the cat bonds. Binary payouts mean a single large event can wipe out a contract entirely rather than partially. And because most ILWs reference US hurricane and US earthquake, they usually add to a fund's exposure to those perils rather than diversifying away from them. Check a fund's shareholder reports for the size of the ILW sleeve and the perils it covers before investing.

Where the Market Is Heading

ILWs are expanding beyond natural catastrophes. In August 2026, Lockton Re placed what it described as the first ILW combining property catastrophe and cyber risk in a single limit. The property trigger references PCS, and the cyber trigger references an industry cyber loss index from PERILS (built with CyberAcuView). In September, MembersCap said it had been the sole investor behind a cat and cyber ILW. Industry cyber loss indices are still young, but if they gain acceptance, ILWs could become one of the main ways insurers transfer cyber catastrophe risk to capital markets.

The other trend is secondary perils. Severe convective storms and wildfires made up more than 80% of global insured losses in 2025, according to the Rochdale fund's adviser, and ILW buyers have responded by seeking cover for those perils as well as peak hurricane and earthquake risk.

Bottom Line

When you evaluate an ILS fund or an industry-loss cat bond, look at the industry loss threshold and the reporting agency before the headline yield. For an ILW sleeve inside a fund, find out its share of assets, which perils it covers, and whether the contracts are binary. Those three facts tell you how a large hurricane or earthquake season would hit the portfolio. For the wider ILS market, including collateralized reinsurance and sidecars, see What Is ILS?.