v3.26.1
Investment Securities
3 Months Ended
Mar. 31, 2026
Investments, Debt and Equity Securities [Abstract]  
Investment Securities Investment Securities
White Mountains’s portfolio of investment securities held for general investment purposes consists of fixed maturity investments, short-term investments, common equity securities, its investment in MediaAlpha and other long-term investments. White Mountains’s portfolio of fixed maturity investments, including those within short-term investments, is classified as trading securities. Trading securities are reported at fair value as of the balance sheet date. Short-term investments also include interest-bearing money market funds and certificates of deposit that are carried at fair value. White Mountains’s portfolio of common equity securities, its investment in MediaAlpha and other long-term investments are measured at fair value. Other long-term investments consist primarily of unconsolidated entities, including Kudu’s Participation Contracts, the Bamboo SPV, PassportCard/DavidShield, the BroadStreet SPV and Bishop Street, as well as private equity funds and hedge funds, a bank loan fund and Lloyd’s trust deposits. White Mountains has generally taken the fair value option for its equity method eligible investments. See Note 16 — Equity Method Eligible Investments.” Net realized and unrealized investment gains (losses) are reported in pre-tax revenues.
Effective December 5, 2025, White Mountains no longer consolidates Bamboo. Through December 5, 2025, White Mountains’s consolidated financial statements included Bamboo’s investment results. See Note 2 — “Significant Transactions.”
White Mountains’s portfolio of investment securities includes investments classified as assets held for sale. See Note 19 — “Held for Sale.”

Net Investment Income

White Mountains’s net investment income is comprised primarily of interest income associated with White Mountains’s fixed maturity investments and short-term investments, dividend income from common equity securities and distributions from other long-term investments.
The following table presents pre-tax net investment income for the three months ended March 31, 2026 and 2025:
Three Months Ended March 31,
Millions20262025
Fixed maturity investments$30.6 $27.0 
Short-term investments15.6 10.6 
Common equity securities.5 .4 
Other long-term investments25.2 22.2 
Total investment income71.9 60.2 
Third-party investment expenses(.5)(.6)
Net investment income, pre-tax$71.4 $59.6 
Net Realized and Unrealized Investment Gains (Losses)

The following table presents net realized and unrealized investment gains (losses) for the three months ended March 31, 2026 and 2025:
Three Months Ended March 31,
Millions20262025
Realized investment gains (losses)
Fixed maturity investments$1.0 $(.1)
Short-term investments .2 
Common equity securities11.2 34.6 
Other long-term investments2.1 5.6 
Net realized investment gains (losses) (1)
14.3 40.3 
Unrealized investment gains (losses)
Fixed maturity investments(23.0)22.2 
Short-term investments(.7)— 
Common equity securities(35.9)(22.1)
Investment in MediaAlpha(65.2)(36.6)
Other long-term investments56.1 46.2 
Net unrealized investment gains (losses)(68.7)9.7 
Net realized and unrealized investment gains (losses) (2)
$(54.4)$50.0 
Fixed maturity and short-term investments
   Net realized and unrealized investment gains (losses)$(22.7)$22.3 
Less: net realized and unrealized gains (losses) on investment
   securities sold during the period
 .5 
Net unrealized investment gains (losses) recognized during the period on
   investment securities held at the end of the period
$(22.7)$21.8 
Common equity securities and investment in MediaAlpha
Net realized and unrealized investment gains (losses) on common
   equity securities
$(24.7)$12.5 
Net realized and unrealized investment gains (losses) from
    investment in MediaAlpha
(65.2)(36.6)
Total net realized and unrealized investment gains (losses) (89.9)(24.1)
Less: net realized and unrealized gains (losses) on investment
   securities sold during the period
.2 3.0 
Net unrealized investment gains (losses) recognized during the period on
   investment securities held at the end of the period
$(90.1)$(27.1)
(1) For the three months ended March 31, 2026 and 2025, includes $(6.4) and $7.2 of net realized and unrealized investment gains (losses) related to foreign currency exchange.
(2) For the three months ended March 31, 2026 and 2025, White Mountains recognized gross realized investment gains of $19.4 and $41.4 and gross realized investment losses of $5.1 and $1.1 on sales of investment securities.

The following table presents total net unrealized gains (losses) attributable to Level 3 investments for the three months ended March 31, 2026 and 2025 for investments still held at the end of the period:
Three Months Ended March 31,
Millions20262025
Total net unrealized investment gains (losses) recognized during the period on Level 3 investments held at the end of period
$50.1 $45.0 
Investment Holdings
The following tables present the cost or amortized cost, gross unrealized investment gains (losses), net foreign currency gains (losses) and carrying value of White Mountains’s fixed maturity investments as of March 31, 2026 and December 31, 2025:
 March 31, 2026
MillionsCost or
Amortized
Cost
Gross
Unrealized
Gains
Gross
Unrealized
Losses
Net Foreign
Currency Gains (Losses)
Carrying
Value
U.S. Government and agency obligations$480.1 $.5 $(2.9)$ $477.7 
Debt securities issued by corporations1,640.1 5.9 (18.5)1.3 1,628.8 
Mortgage and asset-backed securities417.2 2.3 (17.0) 402.5 
Collateralized loan obligations344.7 .3 (.6).8 345.2 
Foreign government and agency obligations31.1  (.3)1.1 31.9 
Total fixed maturity investments
$2,913.2 $9.0 $(39.3)$3.2 $2,886.1 

 December 31, 2025
MillionsCost or
Amortized
Cost
Gross
Unrealized
Gains
Gross
Unrealized
Losses
Net Foreign
Currency
Gains (Losses)
Carrying
Value
U.S. Government and agency obligations$459.7 $1.3 $(.7)$— $460.3 
Debt securities issued by corporations1,534.9 13.5 (11.5).8 1,537.7 
Mortgage and asset-backed securities405.1 4.2 (16.3)— 393.0 
Collateralized loan obligations343.9 .8 (.1)2.4 347.0 
Foreign government and agency obligations31.2 — (.1)1.4 32.5 
Total fixed maturity investments
$2,774.8 $19.8 $(28.7)$4.6 $2,770.5 

The following table presents the cost or amortized cost and carrying value of White Mountains’s fixed maturity investments by contractual maturity as of March 31, 2026 and December 31, 2025. Actual maturities could differ from contractual maturities because borrowers may have the right to call or prepay certain obligations with or without penalties.
March 31, 2026December 31, 2025
MillionsCost or Amortized CostCarrying ValueCost or Amortized CostCarrying Value
Due in one year or less$511.0 $511.1 $455.3 $455.2 
Due after one year through five years1,368.6 1,359.2 1,349.8 1,354.1 
Due after five years through ten years257.0 253.6 199.0 199.3 
Due after ten years14.7 14.5 21.7 21.9 
Mortgage and asset-backed securities and
   collateralized loan obligations
761.9 747.7 749.0 740.0 
Total fixed maturity investments$2,913.2 $2,886.1 $2,774.8 $2,770.5 

The weighted average duration of White Mountains’s fixed maturity investments was 2.6 years and 2.5 years as of March 31, 2026 and December 31, 2025. Including short-term investments, the weighted average duration was 1.7 years and 1.5 years as of March 31, 2026 and December 31, 2025.
The following tables present the cost or amortized cost, gross unrealized investment gains (losses), net foreign currency gains (losses) and carrying value of common equity securities, White Mountains’s investment in MediaAlpha and other long-term investments as of March 31, 2026 and December 31, 2025:
 March 31, 2026
MillionsCost or
Amortized
Cost
Gross
Unrealized
Gains
Gross
Unrealized
Losses
Net Foreign
Currency Gains (Losses)
Carrying
Value
Common equity securities$483.8 $73.4 $(7.6)$(3.1)$546.5 
Investment in MediaAlpha$59.2 $106.9 $ $ $166.1 
Other long-term investments$2,617.8 $782.7 $(133.9)$(13.1)$3,253.5 

 December 31, 2025
MillionsCost or
Amortized
Cost
Gross
Unrealized
Gains
Gross
Unrealized
Losses
Net Foreign
Currency
Gains (Losses)
Carrying
Value
Common equity securities$384.3 $99.9 $— $(1.2)$483.0 
Investment in MediaAlpha$59.2 $172.0 $— $— $231.2 
Other long-term investments$2,378.8 $712.6 $(123.1)$(9.8)$2,958.5 

Fair Value Measurements

Fair value measurements are categorized into a hierarchy that distinguishes between inputs based on market data from independent sources (observable inputs) and a reporting entity’s internal assumptions based upon the best information available when external market data is limited or unavailable (unobservable inputs). Quoted prices in active markets for identical assets or liabilities have the highest priority (Level 1), followed by observable inputs other than quoted prices, including prices for similar but not identical assets or liabilities (Level 2) and unobservable inputs, including the reporting entity’s estimates of the assumptions that market participants would use, having the lowest priority (Level 3).

Fair Value Measurements By Level
White Mountains classifies its portfolio of investment securities by major security type based on the legal form of the securities. White Mountains disaggregates its fixed maturity investments based on the issuing entity type, which impacts credit quality, with debt securities issued by U.S. government entities carrying minimal credit risk, while the credit and other risks associated with other issuers, such as corporations, foreign governments and agencies, entities issuing mortgage and asset-backed securities or entities issuing collateralized loan obligations vary depending on the nature of the issuing entity type. White Mountains further disaggregates debt securities issued by corporations by industry sector because investors often reference commonly used benchmarks and their subsectors to monitor risk and performance. Accordingly, White Mountains further disaggregates this asset class into subclasses based on the similar sectors and industry classifications it uses to evaluate investment risk and performance against commonly used benchmarks, such as the Bloomberg Intermediate U.S. Aggregate Index.
The following tables present White Mountains’s fair value measurements for investments by security type and level as of March 31, 2026 and December 31, 2025:
 March 31, 2026
MillionsFair ValueLevel 1Level 2Level 3
Fixed maturity investments:    
U.S. Government and agency obligations$477.7 $477.7 $ $ 
Debt securities issued by corporations:
Financials589.4  589.4  
Consumer326.0  326.0  
Industrial151.8  151.8  
Healthcare142.9  142.9  
Technology113.6  113.6  
Utilities99.9  99.9  
Materials80.5  80.5  
Communications68.4  68.4  
Energy56.3  56.3  
Total debt securities issued by corporations1,628.8  1,628.8  
Mortgage and asset-backed securities402.5  402.5  
Collateralized loan obligations345.2  345.2  
Foreign government and agency obligations31.9  31.9  
Total fixed maturity investments2,886.1 477.7 2,408.4  
Short-term investments1,501.8 1,496.8 5.0  
Common equity securities:
Exchange-traded funds147.3 147.3   
Other (1)
399.2  399.2  
Total common equity securities
546.5 147.3 399.2  
Investment in MediaAlpha166.1 166.1   
Other long-term investments2,050.4  33.9 2,016.5 
Other long-term investments net asset value (2)
1,203.1    
Total other long-term investments3,253.5  33.9 2,016.5 
Total investments $8,354.0 $2,287.9 $2,846.5 $2,016.5 
(1) Consists of investments in listed funds that predominantly invest in international equities.
(2) Consists of investments in the BroadStreet SPV, private equity funds and hedge funds, a bank loan fund, Lloyd’s trust deposits and insurance-linked securities (“ILS”) funds for which fair value is measured using NAV as a practical expedient. Investments for which fair value is measured at NAV are not classified within the fair value hierarchy.
December 31, 2025
MillionsFair ValueLevel 1Level 2Level 3
Fixed maturity investments:    
U.S. Government and agency obligations$460.3 $460.3 $— $— 
Debt securities issued by corporations:
Financials531.5 — 531.5 — 
Consumer306.2 — 306.2 — 
Industrial150.0 — 150.0 — 
Healthcare146.1 — 146.1 — 
Technology98.4 — 98.4 — 
Utilities90.4 — 90.4 — 
Materials78.7 — 78.7 — 
Communications76.3 — 76.3 — 
Energy60.1 — 60.1 — 
Total debt securities issued by corporations1,537.7 — 1,537.7 — 
Mortgage and asset-backed securities393.0 — 393.0 — 
Collateralized loan obligations347.0 — 347.0 — 
Foreign government and agency obligations32.5 — 32.5 — 
Total fixed maturity investments2,770.5 460.3 2,310.2 — 
Short-term investments1,881.7 1,871.7 10.0 — 
Common equity securities:
Exchange-traded funds30.7 30.7 — — 
Other (1)
452.3 — 452.3 — 
Total common equity securities483.0 30.7 452.3 — 
Investment in MediaAlpha231.2 231.2 — — 
Other long-term investments1,848.1 — 33.7 1,814.4 
Other long-term investments NAV (2)
1,110.4 — — — 
Total other long-term investments2,958.5 — 33.7 1,814.4 
Total investments$8,324.9 $2,593.9 $2,806.2 $1,814.4 
(1) Consists of investments in listed funds that predominantly invest in international equities.
(2) Consists of investments in the BroadStreet SPV, private equity funds and hedge funds, a bank loan fund, Lloyd’s trust deposits and ILS funds for which fair value is measured using NAV as a practical expedient. Investments for which fair value is measured at NAV are not classified within the fair value hierarchy.
Investments Held on Deposit or as Collateral

Lloyd’s trust deposits are generally required of Lloyd's syndicates to protect policyholders in non-U.K. markets and are pledged into Lloyd’s trust accounts to provide a portion of the capital needed to support obligations at Lloyd’s. As of March 31, 2026 and December 31, 2025, Ark held Lloyd’s trust deposits with a fair value of $176.4 million and $180.4 million.
The underwriting capacity of a member of Lloyd’s must be supported by providing a deposit (“Funds at Lloyd’s”) in the form of cash, securities or letters of credit in an amount determined by Lloyd’s. The amount of such deposit is calculated for each member through an annual capital adequacy determination by Lloyd’s. As of March 31, 2026 and December 31, 2025, the fair value of Ark’s Funds at Lloyd’s cash and investment deposits totaled $353.7 million and $361.6 million.
As of March 31, 2026 and December 31, 2025, Ark held additional investments on deposit or as collateral for insurance regulators and reinsurance counterparties of $253.6 million and $257.2 million.
As of March 31, 2026 and December 31, 2025, investments of $117.7 million and $245.7 million were held in a collateral trust account required to be maintained in relation to WM Outrigger Re’s reinsurance agreement with GAIL.
Ark is required to pledge collateral under its standby letters of credit. See Note 7 — “Debt.”
Kudu is required to maintain an interest reserve account in connection with its credit facility. See Note 7 - “Debt.”
HG Re is required to maintain assets, including investments, in collateral trusts under the first-loss reinsurance treaty (“FLRT”) with BAM. See Note 10 — “Municipal Bond Guarantee Reinsurance.”
HG Global is required to maintain an interest reserve account in connection with its senior notes. See Note 7 — “Debt.”
As of March 31, 2026 and December 31, 2025, investments of $56.0 million and $56.8 million were held on deposit, primarily related to amounts held on behalf of Distinguished’s insurance carrier partners and certain insureds.

Debt Securities Issued by Corporations

The following table presents the fair values for credit ratings of debt securities issued by corporations held in White Mountains’s investment portfolio as of March 31, 2026 and December 31, 2025:
Fair Value at
MillionsMarch 31, 2026December 31, 2025
AAA$7.3 $7.8 
AA85.5 89.9 
A767.1 711.7 
BBB755.4 716.9 
BB5.5 3.2 
Other8.0 8.2 
Debt securities issued by corporations (1)
$1,628.8 $1,537.7 
(1) Credit ratings are based upon issuer credit ratings provided by Standard & Poor’s Financial Services LLC (“Standard & Poor’s”), or if unrated by Standard & Poor’s, long-term obligation ratings provided by Moody’s Investor Service, Inc.
Mortgage and Asset-backed Securities and Collateralized Loan Obligations

The following table presents the fair value of White Mountains’s mortgage and asset-backed securities and collateralized loan obligations as of March 31, 2026 and December 31, 2025:
 March 31, 2026December 31, 2025
MillionsFair ValueLevel 2Level 3Fair ValueLevel 2Level 3
Mortgage-backed securities:      
Agency:      
FNMA$201.2 $201.2 $ $192.1 $192.1 $— 
FHLMC136.2 136.2  141.3 141.3 — 
GNMA20.0 20.0  20.6 20.6 — 
   Total agency (1)
357.4 357.4  354.0 354.0 — 
   Total mortgage-backed securities357.4 357.4  354.0 354.0 — 
Other asset-backed securities:
Vehicle receivables26.2 26.2  21.9 21.9 — 
Credit card receivables13.9 13.9  14.0 14.0 — 
Other5.0 5.0  3.1 3.1 — 
Total other asset-backed securities45.1 45.1  39.0 39.0 — 
Total mortgage and asset-backed securities402.5402.5 393.0393.0— 
Collateralized loan obligations345.2 345.2  347.0 347.0 — 
Total mortgage and asset-backed securities
   and collateralized loan obligations
$747.7 $747.7 $ $740.0 $740.0 $— 
(1)    Represents publicly traded mortgage-backed securities which carry the full faith and credit guarantee of the U.S. Government (i.e., GNMA) or are guaranteed by a government sponsored entity (i.e., FNMA, FHLMC).

As of March 31, 2026 and December 31, 2025, White Mountains’s investment portfolio included $345.2 million and $347.0 million of collateralized loan obligations that are within the senior tranches of their respective fund securitization structures. All of White Mountains’s collateral loan obligations were rated AAA or AA as of March 31, 2026 and December 31, 2025.

Investment in MediaAlpha

White Mountains’s investment in MediaAlpha is accounted for at fair value based on the publicly traded share price of MediaAlpha’s common stock and is presented as a separate line item on the balance sheet.
As of March 31, 2026, White Mountains owned 17.9 million shares of MediaAlpha, representing a 28.4% basic ownership interest based on the total class A and class B common shares outstanding. At the March 31, 2026 share price of $9.30, the fair value of White Mountains’s investment in MediaAlpha was $166.1 million. At White Mountains’s March 31, 2026 level of ownership, each $1.00 per share increase or decrease in the share price of MediaAlpha will result in an approximate $7.00 per share increase or decrease in White Mountains’s book value per share.
As of December 31, 2025, White Mountains owned 17.9 million shares of MediaAlpha, representing a 27.7% basic ownership interest based on the total class A and class B common shares outstanding. At the December 31, 2025 share price of $12.95, the fair value of White Mountains’s investment in MediaAlpha was $231.2 million.
Other Long-Term Investments

The following tables present the carrying values of White Mountains’s other long-term investments by reportable segment as of March 31, 2026 and December 31, 2025:
Fair Value as of March 31, 2026
MillionsArk/ WM OutriggerKuduOtherTotal
Kudu’s Participation Contracts $ $1,352.2 $ $1,352.2 
Bamboo SPV
— — 260.0 260.0 
BroadStreet SPV
  170.1 170.1 
PassportCard/DavidShield
  170.0 170.0 
Bishop Street
  125.0 125.0 
Other unconsolidated entities (1)
  113.5 113.5 
Total unconsolidated entities 1,352.2 838.6 2,190.8 
Private equity funds and hedge funds219.6  257.2 476.8 
Bank loan fund307.8   307.8 
Lloyd’s trust deposits 176.4   176.4 
ILS funds  51.0 51.0 
Private debt instruments 6.6 10.2 16.8 
Other33.9   33.9 
Total other long-term investments$737.7 $1,358.8 $1,157.0 $3,253.5 
(1) Includes White Mountains’s noncontrolling equity interests in certain preferred securities, common shares, limited partnership units and limited liability company units.
Fair Value as of December 31, 2025
MillionsArk/ WM OutriggerKuduOtherTotal
Kudu’s Participation Contracts $— $1,285.0 $— $1,285.0 
Bamboo SPV
— — 250.0 250.0 
BroadStreet SPV
— — 160.0 160.0 
PassportCard/DavidShield
— — 170.0 170.0 
Other unconsolidated entities (1)
— — 108.7 108.7 
Total unconsolidated entities— 1,285.0 688.7 1,973.7 
Private equity funds and hedge funds167.1 — 228.1 395.2 
Bank loan fund308.5 — — 308.5 
Lloyd’s trust deposits 180.4 — — 180.4 
ILS funds— — 50.1 50.1 
Private debt instruments— 6.4 10.5 16.9 
Other33.7 — — 33.7 
Total other long-term investments$689.7 $1,291.4 $977.4 $2,958.5 
(1) Includes White Mountains’s noncontrolling equity interests in certain preferred securities, common shares, limited partnership units and limited liability company units.

Private Equity Funds and Hedge Funds
White Mountains invests in private equity funds and hedge funds, which are included in other long-term investments. The fair value of these investments is generally estimated using the NAV of the funds. As of March 31, 2026, White Mountains held investments in seventeen private equity funds and two hedge funds. The largest investment in a single private equity fund or hedge fund was $162.6 million and $110.6 million as of March 31, 2026 and December 31, 2025.
The following table presents the fair value of investments and unfunded commitments in private equity funds and hedge funds by investment objective and sector as of March 31, 2026 and December 31, 2025:
 March 31, 2026December 31, 2025
MillionsFair ValueUnfunded
Commitments
Fair ValueUnfunded
Commitments
Private equity funds    
Aerospace/Defense/Government$138.1 $38.0 $144.0 $39.9 
Financial services108.0 20.8 104.2 23.7 
Real estate3.0 2.2 3.0 2.2 
Total private equity funds249.1 61.0 251.2 65.8 
Hedge funds   
Long/short all cap global162.6  110.6 — 
Long/short equity financials and business services65.1  33.4 — 
Total hedge funds227.7  144.0 — 
Total private equity funds and hedge funds$476.8 $61.0 $395.2 $65.8 
 
Investments in private equity funds are generally subject to a lock-up period during which investors may not request a redemption. Distributions prior to the expected termination date of the fund may be limited to dividends or proceeds arising from the liquidation of the fund’s underlying investments. In addition, certain private equity funds have the option to extend the lock-up period.
The following table presents investments in private equity funds that were subject to lock-up periods as of March 31, 2026:
Millions1 – 3 years3 – 5 years5 – 10 yearsTotal
Private equity funds — expected lock-up period remaining$54.7$7.8$186.6$249.1

Investors in private equity funds are generally subject to indemnification obligations outside of the capital commitment period and prior to the winding up of the fund. As of March 31, 2026 and December 31, 2025, White Mountains is not aware of any indemnification claims relating to its investments in private equity funds. 
Redemption of investments in most hedge funds is subject to restrictions, including lock-up periods where no redemptions or withdrawals are allowed, restrictions on redemption frequency and advance notice periods for redemptions. Amounts requested for redemptions remain subject to market fluctuations until the redemption effective date, which generally falls at the end of the defined redemption period. White Mountains’s hedge fund investments are subject to monthly and quarterly restrictions on redemptions and advance written redemption notice period requirements that range between 45 and 90 calendar days.

Bank Loan Fund
White Mountains’s other long-term investments include a bank loan fund with a fair value of $307.8 million and $308.5 million as of March 31, 2026 and December 31, 2025. The fair value of this investment is estimated using the NAV of the fund. The bank loan fund’s investment objective is to provide, on an unleveraged basis, high current income consistent with preservation of capital and low duration. The bank loan fund primarily invests in a broad portfolio of U.S. dollar-denominated, non-investment grade, floating-rate senior secured loans and may invest in other financial instruments, such as secured and unsecured corporate debt, credit default swaps, reverse repurchase agreements, synthetic indices and cash and cash equivalents.
The investment in the bank loan fund is subject to restrictions on redemption frequency and advance notice periods for redemptions. Amounts requested for redemptions remain subject to market fluctuations until the redemption effective date, which generally falls at the end of the defined redemption period. White Mountains may redeem all or a portion of its bank loan fund investment as of any calendar month-end upon 15 calendar days advanced written notice.
Lloyd’s Trust Deposits
White Mountains’s other long-term investments include Lloyd’s trust deposits, which consist of non-U.K. deposits and Canadian commingled pooled funds. The Lloyd’s trust deposits invest primarily in short-term government securities, agency securities and corporate bonds held in trusts that are managed by Lloyd's of London. These investments are generally required of Lloyd's syndicates to protect policyholders in non-U.K. markets and are pledged into Lloyd’s trust accounts to provide a portion of the capital needed to support obligations at Lloyd’s. The fair value of the Lloyd’s trust deposits is generally estimated using the NAV of the funds. As of March 31, 2026 and December 31, 2025, White Mountains held Lloyd’s trust deposits with a fair value of $176.4 million and $180.4 million.

ILS Funds
White Mountains’s other long-term investments include ILS fund investments. The fair value of these investments is generally estimated using the NAV of the funds. As of March 31, 2026 and December 31, 2025, White Mountains held investments in ILS funds with a fair value of $51.0 million and $50.1 million.
Investments in ILS funds are generally subject to restrictions, including lock-up periods where no redemptions or withdrawals are allowed, non-renewal clauses, restrictions on redemption frequency and advance notice periods for redemptions. From time to time, natural catastrophe, liquidity, market or other events will occur that make the determination of fair value for underlying investments in ILS funds less certain due to the potential for loss development. In such circumstances, the impacted investments may be subject to additional lock-up provisions.
ILS funds are typically subject to monthly and annual restrictions on redemptions and advance redemption notice period requirements that range between 30 and 90 calendar days. Amounts requested for redemption remain subject to market fluctuations until the redemption effective date, which is generally at the end of the defined redemption period or when the underlying investment has fully matured or been commuted.

Infrastructure Fund
In 2025, Ark made a $100.0 million commitment to invest in an open-ended, pooled investment fund focused on making equity investments in essential service infrastructure assets. The fund has a 4-year lock-up period, subject to the discretion of the manager. Redemptions of all or a portion of the fund are allowable semi-annually with a 90-day written notice. Ark anticipates that the initial capital call will occur in the second half of 2026.

Rollforward of Level 3 Investments

Level 3 measurements as of March 31, 2026 and 2025 consist of securities for which the estimated fair value has not been determined based upon quoted market price inputs for identical or similar securities. The following table presents the changes in White Mountains’s fair value measurements for Level 3 investments for the three months ended March 31, 2026 and 2025:
Level 3 Investments
Other long-term investments
MillionsMarch 31, 2026March 31, 2025
Beginning balance
$1,814.4 $1,262.7 
Net realized and unrealized gains50.1 45.0 
Purchases and contributions152.0 68.2 
Sales and distributions — 
Transfers in — 
Transfers out — 
Ending balance
$2,016.5 $1,375.9 
Significant Unobservable Inputs

The following tables present significant unobservable inputs used in estimating the fair value of White Mountains’s other long-term investments, classified within Level 3 as of March 31, 2026 and December 31, 2025. The tables below exclude $125.4 million and $250.4 million of Level 3 other long-term investments generally valued based on recent or expected transaction prices. As of December 31, 2025, the Bamboo SPV was measured at fair value based on the value implied in the Bamboo Sale Transaction. See Note 2 — “Significant Transactions.” The fair value of investments in the BroadStreet SPV, private equity funds and hedge funds, bank loan funds, Lloyd’s trust deposits and ILS funds are generally estimated using NAV. Investments for which fair value is measured at NAV are not classified within the fair value hierarchy.
$ in Millions
March 31, 2026
Description
Valuation Technique(s) (1)
Fair Value (2)
Unobservable Inputs
Discount Rate (5)
Terminal Cash Flow Exit Multiple (x) or Terminal Revenue Growth Rate (%) (5)
Kudu’s Participation Contracts (3) (4)
Discounted cash flow
$1,352.2
16% - 24%
7x - 22x
Bamboo SPV
Discounted cash flow
$260.016%4%
PassportCard/DavidShieldDiscounted cash flow$170.024%4%
Private common shares and units
Discounted cash flow
$56.9
22% - 35%
3% - 4%
Private preferred securities
Discounted cash flow$35.615%N/A
Private debt instrumentsDiscounted cash flow$16.4
11% - 12%
N/A
(1) Key inputs to the discounted cash flow analysis generally include projections of future revenue and earnings, discount rates and terminal exit multiples or growth rates.
(2) Includes the net unrealized investment gains (losses) associated with foreign currency; foreign currency effects based on observable inputs.
(3) Since Kudu’s Participation Contracts are not subject to corporate taxes within Kudu Investment Management, LLC, pre-tax discount rates are applied to pre-tax cash flows in determining fair values. The weighted average discount rate and weighted average terminal cash flow exit multiple applied to Kudu’s Participation Contracts was 19% and 14x.
(4) In the first three months of 2026, Kudu contributed $25.4 into new and existing Participation Contracts.
(5) Increases (decreases) to the discount rates in isolation would result in lower (higher) fair value measurements, while increases (decreases) to the terminal cash flow exit multiples or terminal revenue growth rates in isolation would result in higher (lower) fair value measurements.

$ in MillionsDecember 31, 2025
Description
Valuation Technique(s) (1)
Fair Value (2)
Unobservable Inputs
Discount Rate (5)
Terminal Cash Flow Exit Multiple (x) or Terminal Revenue Growth Rate (%) (5)
Kudu’s Participation Contracts (3) (4)
Discounted cash flow
$1,285.0
16% - 25%
7x - 22x
PassportCard/DavidShield Discounted cash flow$170.024%4%
Private common shares and units
Discounted cash flow$56.9
22% - 35%
3% - 4%
Private preferred securities
Discounted cash flow$35.68%N/A
Private debt instrumentsDiscounted cash flow$16.5
11% - 12%
N/A
(1) Key inputs to the discounted cash flow analysis generally include projections of future revenue and earnings, discount rates and terminal exit multiples or growth rates.
(2) Includes the net unrealized investment gains (losses) associated with foreign currency; foreign currency effects based on observable inputs.
(3) Since Kudu’s Participation Contracts are not subject to corporate taxes within Kudu Investment Management, LLC, pre-tax discount rates are applied to pre-tax cash flows in determining fair values. The weighted average discount rate and weighted average terminal cash flow exit multiple applied to Kudu’s Participation Contracts was 19% and 14x.
(4) In 2025, Kudu contributed $201.7 into new and existing Participation Contracts.
(5) Increases (decreases) to the discount rates in isolation would result in lower (higher) fair value measurements, while increases (decreases) to the terminal cash flow exit multiples or terminal revenue growth rates in isolation would result in higher (lower) fair value measurements.