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Insurance companies: pooling risk and investing premiums
· Institution or agency
Fact, law or dataA rule, statute, definition or measured number.
Insurers collect premiums up front, pay claims later and invest the money in between, mostly in bonds.
See it on the Money & Finance map →How it works
Life insurers sell policies and annuities that pay out over decades, so they buy long-term bonds whose payments match those dates. Property and casualty insurers cover homes, buildings, cars and liability, with shorter, lumpier claims, so they hold more cash and stocks. The pool of premiums waiting to be paid out is called float. Unlike banks, insurers are regulated by the states, coordinated by the NAIC; state guaranty funds, with limits that vary, back policyholders if an insurer fails.
Why it matters
They are among the largest bond buyers and big commercial mortgage lenders. AIG's 2008 rescue showed an insurer can threaten the whole system too.
Think of it like
Like a building's capital reserve fund: money collected today, held and invested, to pay big bills that arrive years later.
Facts, rules and data
NAIC annual industry statistics and the Fed's Financial Accounts track insurer assets; Warren Buffett's Berkshire Hathaway shareholder letters explain float in plain language.
Debates and risks
Regulators debate whether private-equity-owned insurers, investing annuity money in private credit and reinsuring it offshore in Bermuda, are taking hidden risks.
Connections (4)
▸Insurance companies: pooling risk and investing premiums are among the biggest holders of Corporate bonds and credit spreadsFact, law or data
The connection
Life insurers owe steady payments for decades, so they buy long investment-grade corporate bonds that pay more than Treasuries on a predictable schedule. State capital rules charge more for lower ratings, so insurers cluster in the A and BBB grades. They also buy private placements, bonds sold directly to them rather than to the public.
When and why
A practice dating to 19th-century railroad bonds; today US life insurers hold trillions of dollars of corporate bonds, per Fed data.
How we know
The Fed's Financial Accounts (Z.1) list bond holdings by type of investor; the NAIC publishes insurers' portfolios and rating mix.
Debates and risks
Regulators debate whether insurers' drift toward BBB and privately rated bonds, often graded by smaller agencies, understates their risk.
▸Warren Buffett and value investing built Berkshire on the float of Insurance companies: pooling risk and investing premiumsFact, law or data
The connection
Insurers collect premiums now and pay claims later; the money held in between, called 'float', can be invested. Buffett bought National Indemnity in 1967, later GEICO and General Re, and invested their float in stocks and whole companies. When underwriting is profitable, float is better than a free loan, like holding tenants' security deposits for years.
When and why
Omaha: National Indemnity in 1967 for about $8.6 million, full ownership of GEICO in 1996, General Re in 1998. Float reached about $170 billion by 2024.
How we know
Buffett reports float every year in his shareholder letters, backed by Berkshire's audited filings.
Debates and risks
Whether the float model works as well under new CEO Greg Abel, and how larger catastrophe losses from wildfires and storms affect it.
▸Insurance companies: pooling risk and investing premiums increasingly fund Private credit fundsFact, law or data
The connection
Private-equity firms bought or partnered with life insurers, such as Apollo with Athene and KKR with Global Atlantic. They invest annuity premiums in private loans and asset-backed credit their own funds originate, earning extra yield. Insurers have become one of private credit's biggest sources of long-term money.
When and why
Apollo founded Athene in 2009 and merged with it in 2022; KKR bought into Global Atlantic from 2021; Blackstone and Brookfield made similar moves.
How we know
NAIC data show private and privately rated assets rising in insurer portfolios; the Fed, the IMF and the Bank for International Settlements have flagged the trend.
Debates and risks
Whether the extra yield reflects skill or hidden risk is unproven; Bermuda reinsurance and manager-set valuations make insurers' exposure hard to judge.
▸Life insurance company loans: low leverage, long fixed rates are made by Insurance companies: pooling risk and investing premiumsFact, law or data
The connection
Life insurers owe policyholders money decades from now, so they invest in long, steady assets. Low-leverage commercial mortgages pay more than similar corporate bonds and rarely default. Insurers keep the loans on their own books, which is why they lend directly and fix rates for long terms.
When and why
US life insurers such as MetLife, PGIM, Northwestern Mutual, New York Life, MassMutual and Principal held about $774 billion of CRE mortgages at end-2025 (MBA).
How we know
Insurers' statutory filings with the NAIC, which grade each mortgage's risk for capital, and MBA debt-outstanding data.
Debates and risks
MBA counts only whole loans; insurers also own much CMBS, so their full CRE exposure exceeds the 16% share.