Definition:Float
🏦 Float is the pool of money that an insurance carrier holds between the time premiums are collected from policyholders and the time claims are paid out. Because insurance is a "collect now, pay later" business, this timing gap creates a reservoir of investable capital that can generate significant investment income. The concept is central to the economics of insurance — Warren Buffett has famously described Berkshire Hathaway's insurance float as the engine behind the conglomerate's investment strategy.
📈 Carriers receive premiums upfront, often months or years before claims arise. During that interval, the funds are invested in bonds, equities, real estate, and other instruments. In long-tail lines such as workers' compensation or general liability, where claims may not be settled for a decade or more, float can remain invested for extended periods, amplifying its value. The size and duration of float depend on the underwriting mix: a company writing mostly short-tail property business will generate float that turns over quickly, while a reinsurer focused on casualty treaties will hold funds far longer.
⚖️ What makes float so powerful — and so perilous — is that it functions like borrowed money, but only "free" if the carrier's combined ratio stays at or below 100%. When underwriting losses exceed investment returns, the cost of float turns negative and erodes capital. Regulators pay close attention to how carriers invest their float, imposing asset-liability management requirements and risk-based capital standards to prevent excessive risk-taking. For insurtech startups building new carrier models, understanding and managing float is a critical hurdle — it separates companies that can self-fund growth from those that remain dependent on external capital.
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