Secondary Perils
Definition
Secondary perils are catastrophe types that occur more often but usually cause smaller individual events than the peak perils of hurricane and major earthquake: severe convective storms (hail, tornadoes, high winds), wildfire, winter storms and flood. Individually they rarely reach high per-event layers, but together they drive much of insurers' annual catastrophe losses and can erode aggregate covers and frequency-exposed ILS.
Why it matters
Investors in occurrence cat bonds at high layers are mostly exposed to peak perils; investors in aggregate covers, quota-share sidecars and lower layers are heavily exposed to secondary perils. A fund holding mostly sidecars and collateralized reinsurance should be judged on how it fared in years like 2025, when secondary perils, not hurricanes, set the losses.
Common misconceptions
- •Secondary does not mean minor; wildfire and hail years can rival hurricane years in insured loss.
- •A quiet hurricane season does not mean a quiet catastrophe year.
- •Per-event layers and aggregate layers respond very differently to the same secondary-peril year.
- •The label is only a starting point. Investor outcomes usually depend on the governing documents, cash-flow priority, valuation policy, disclosure quality, and manager discretion surrounding the term, not just the shorthand definition used in marketing materials.
Technical details
Allstate catastrophe losses by type (2025 10-K, $ millions)
2025: wind/hail 3,952 (110 events), wildfires 1,049 (4), hurricanes/tropical storms 0, total 4,959.
2024: wind/hail 3,832 (113), hurricanes 1,180 (5), wildfires 71 (10), total 4,964.
Gross 2025 losses before reinsurance recoverables and reinstatement premiums: $6.2 billion.
How investors apply the term
Investors usually apply this term by tying the definition back to the controlling documents and then asking which cash flows, rights, restrictions, or valuation assumptions it changes. A useful review looks at the term alongside fees, leverage, liquidity, reporting frequency, and manager discretion rather than treating it as a standalone concept.
The practical diligence test is simple: identify who benefits if the assumption is wrong, who has control when conditions change, and what evidence the investor receives after closing. Terms that cannot be reconciled to documents, cash movements, and monitoring data should be treated as marketing shorthand until proven otherwise.
Frequently asked questions
- How large can secondary perils be?
- Allstate's 2025 10-K shows $4.96 billion of catastrophe losses for 2025 with no hurricane losses at all: $3.95 billion from 110 wind and hail events and $1.05 billion from four wildfire events. In 2024, hurricanes accounted for $1.18 billion of a similar total.
- Do secondary perils reach reinsurance?
- Yes, when events are large or covers are aggregate. Allstate says its 2025 ceded catastrophe losses were 'driven by the California wildfires,' and it recorded $44 million of current-year and $60 million of prior-year nationwide aggregate reinsurance recoveries.
- Why are they a modeling concern?
- Because their frequency, building values and claims costs have changed faster than long-run catalogs. RenaissanceRe's 2025 10-K lists 'a series of wildfires that burned throughout southern California in January 2025' among its 2025 large loss events.