Business Overview: MGIC Investment Corporation (NYSE: MTG)

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Executive Summary

MGIC Investment Corporation is the holding company for Mortgage Guaranty Insurance Corporation (MGIC), one of the largest private mortgage insurers (PMI) in the United States. Through its subsidiaries, MGIC insures lenders against borrower default on low-down-payment residential mortgages, allowing those loans to be sold to Fannie Mae and Freddie Mac (the GSEs) under their charter requirements.

Headquartered in Milwaukee, Wisconsin, MGIC wrote $60.2 billion of new primary insurance in 2025 and held $303.1 billion of primary insurance in force at year-end, generating about $1.2 billion in total revenue and $738 million of net income. Its business sits structurally downstream of U.S. housing-finance policy: it exists because federal law requires credit enhancement on GSE loans with down payments below 20%.

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1. Core Business Model & How They Work

MGIC collects a stream of monthly premiums in exchange for covering a contractual share of lender losses if an insured borrower defaults and the home is foreclosed.

[ Lender originates low-down-payment loan ] ➡️ [ MGIC writes primary mortgage insurance (NIW) ]
        ➡️ [ Lender sells loan to Fannie Mae / Freddie Mac ] ➡️ [ MGIC collects monthly premiums ]
        ➡️ [ MGIC cedes risk via reinsurance (QSR/XOL) to reduce required capital ]
        ➡️ [ If borrower defaults: MGIC pays a claim, or loan cures/is modified ]

Key Operational Drivers

1. Premium economics: About 97% of 2025 new insurance written used monthly premium plans, so revenue accrues over the life of the policy rather than upfront — a long-duration, annuity-like premium stream.
2. Capital discipline (PMIERs): MGIC must hold "Available Assets" above GSE-mandated "Minimum Required Assets." Reinsurance (quota-share and excess-of-loss) reduces this capital charge, but only to the extent the GSEs grant capital credit for it.
3. Investment income: A roughly $5.8 billion investment-grade fixed-income portfolio supplements underwriting income.
4. Credit risk transfer (CRT): MGIC also participates in GSE CRT programs, covering reference pools of mortgages the GSEs already acquired (about $482 million of risk at year-end 2025) — a secondary, capital-markets-adjacent revenue stream.

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2. Product Portfolio

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3. Competitive Landscape

      PRICING / RISK SELECTION DISCIPLINE
            High  ▲
                  │        [MGIC]  [Other 5 Active PMIs]
                  │
                  │
                  │
            Low   └──────────────────────────────► 
                  Low        GOVERNMENT SUBSTITUTE        High
                         (FHA / VA / USDA)

• Government programs (FHA, VA, USDA): Together accounted for ~62% of 2025 low-down-payment originations subject to credit enhancement — MGIC's largest single competitive force, since borrowers can choose FHA insurance instead of private MI.
• Other private mortgage insurers: Six PMI companies actively compete for the same flow business on price, underwriting guidelines, and service; MGIC held ~19.4% NIW market share in 2025 (up from 18.6% in 2024).
• GSE capital-markets alternatives: Lender self-insurance structures and "piggyback" second-lien loans can substitute for traditional MI, and GSE CRT transactions compete with ceded reinsurance capacity.

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4. Strategic Strengths & Risks

Strengths (The Moat)

• Regulatory gatekeeping: GSE and state regulatory approval to write business is a real barrier — a new entrant needs both state licenses and GSE "qualified insurer" status under PMIERs.
• Scale and underwriting data: Decades of loan-level performance data across cycles support more precise risk-based pricing.
• Market share gains: NIW share rose for a second consecutive year, suggesting pricing and underwriting competitiveness versus the other five PMIs.

Risks

1. GSE/housing-policy dependence: Any reform that reduces the GSEs' role (or releases them from conservatorship with different capital rules) could restructure the entire PMI industry overnight.
2. PMIERs capital treatment of reinsurance: The GSEs can tighten the capital credit given for ceded reinsurance, forcing MGIC to hold more capital or cut back NIW.
3. Credit cycle lumpiness: MGIC only reserves for loans already delinquent, so a sudden downturn in employment or home prices can produce a sharp, hard-to-predict jump in incurred losses (2025 incurred losses of $48.9 million versus a $14.9 million benefit in 2024).
4. Customer concentration: The single largest lender customer was ~11% of direct earned premiums.

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5. Financial Overview

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6. Summary Conclusion

MGIC occupies a regulated, capital-intensive niche inside the U.S. housing-finance system: it is paid to absorb default risk the GSEs are required to lay off, and its ability to do so profitably depends on disciplined underwriting, efficient reinsurance capital management, and continued GSE/FHA policy stability. The business model is durable as long as low-down-payment lending and the GSE charter requirement persist, but it is also a leveraged bet on the U.S. housing and credit cycle — and on political decisions about GSE reform that MGIC itself cannot control.