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Manning Rountree
Chief Executive Officer at
White Mountains Advisors LLC
Net worth: 39 M $ as of 2026-07-30
Profile
George Manning Rountree is Chief Executive Officer at White Mountains Advisors LLC since 2004.
Mr. Rountree is Chairman at Build America Mutual Assurance Co. since 2020.
Mr. Rountree was Chief Executive Officer & Director at White Mountains Insurance Group Ltd. from 2017 to 2025.
Mr. Rountree was Independent Non-Executive Director at Admiral Group Plc from 2015 to 2021.
Mr. Rountree was Managing Director at White Mountains Capital LLC.
Mr. Rountree was Director at QL Holdings LLC.
Mr. Rountree was Director at Wobi Insurance Agency Ltd. Mr. Rountree was Director at Removal Stars Ltd. Mr. Rountree was Senior Vice President at Putnam U.S.
Holdings.
I LLC from 2002 to 2004.
Mr. Rountree was Principal at McKinsey & Co., Inc. from 1999 to 2002.
Mr. Rountree was President at WM Advisors, Inc. from 2009 to 2014.
Known holdings in public companies
| Company | Date | Number of shares | Valuation | Valuation date |
|---|---|---|---|---|
| 2026-03-29 | 18,568 ( 0.75% ) | 39 M $ | 2026-07-30 |
Manning Rountree active positions
| Companies | Position | Start |
|---|---|---|
White Mountains Advisors LLC
 White Mountains Advisors LLC Investment ManagersFinance WMA’s investment approach generally places emphasis on maximizing long-term total returns (after-tax) while taking prudent levels of risk and maintaining a diversified portfolio. The firm manages a broad array security types in the following categories: debt securities, equity securities, alternative investments, cash or cash equivalents and derivatives. Their investments in equity securities include ETFs, common stock, preferred stock, convertible preferred stock and warrants. Investments in debt securities include debt issued by (1) domestic and foreign corporations (public and private), governments, government agencies, government sponsored entities, and supranational entities; (2) mortgage-backed securities, including collateralized mortgage obligations, whole loans, and agency pass-through securities; and (3) asset backed securities, including securities backed by consumer debt, loans/leases and similar economic interests, loan participations and convertible bonds. | Chief Executive Officer | - |
Build America Mutual Assurance Co.
 Build America Mutual Assurance Co. Financial ConglomeratesFinance Operates as a mutual municipal bond insurance company | Chairman | 2020-05-06 |
Former positions of Manning Rountree
| Companies | Position | End |
|---|---|---|
| WHITE MOUNTAINS INSURANCE GROUP, LTD. | Chief Executive Officer | 2025-12-30 |
| ADMIRAL GROUP PLC | Director/Board Member | 2021-06-16 |
WM Advisors, Inc.
 WM Advisors, Inc. Investment ManagersFinance Provides financial advisory services | President | 2014-11-30 |
Putnam U.S. Holdings I LLC
 Putnam U.S. Holdings I LLC Investment ManagersFinance Provides asset management services | Corporate Officer/Principal | 2003-12-31 |
McKinsey & Co., Inc.
 McKinsey & Co., Inc. Miscellaneous Commercial ServicesCommercial Services Operates as a management consulting firm | Corporate Officer/Principal | 2001-12-31 |
Experiences
Positions held
Active
Inactive
Listed companies
Private companies
Connections
70
1st degree connections
11
1st degree companies
Male
Female
Members of the board
Executives
Linked companies
| Private companies | 11 |
|---|---|
White Mountains Insurance Group Ltd.
 White Mountains Insurance Group Ltd. Multi-Line InsuranceFinance Provides property and casualty insurance services | Finance |
Admiral Group Plc
 Admiral Group Plc Property/Casualty InsuranceFinance Provides motor insurance services | Finance |
Putnam U.S. Holdings I LLC
Putnam U.S. Holdings I LLC Investment ManagersFinance Provides asset management services | Finance |
McKinsey & Co., Inc.
McKinsey & Co., Inc. Miscellaneous Commercial ServicesCommercial Services Operates as a management consulting firm | Commercial Services |
White Mountains Advisors LLC
White Mountains Advisors LLC Investment ManagersFinance WMA’s investment approach generally places emphasis on maximizing long-term total returns (after-tax) while taking prudent levels of risk and maintaining a diversified portfolio. The firm manages a broad array security types in the following categories: debt securities, equity securities, alternative investments, cash or cash equivalents and derivatives. Their investments in equity securities include ETFs, common stock, preferred stock, convertible preferred stock and warrants. Investments in debt securities include debt issued by (1) domestic and foreign corporations (public and private), governments, government agencies, government sponsored entities, and supranational entities; (2) mortgage-backed securities, including collateralized mortgage obligations, whole loans, and agency pass-through securities; and (3) asset backed securities, including securities backed by consumer debt, loans/leases and similar economic interests, loan participations and convertible bonds. | Finance |
White Mountains Capital LLC
 White Mountains Capital LLC Property/Casualty InsuranceFinance Provides property and casualty insurance services | Finance |
QL Holdings LLC
 QL Holdings LLC Advertising/Marketing ServicesCommercial Services Provides internet advertising solutions | Commercial Services |
WM Advisors, Inc.
WM Advisors, Inc. Investment ManagersFinance Provides financial advisory services | Finance |
Build America Mutual Assurance Co.
Build America Mutual Assurance Co. Financial ConglomeratesFinance Operates as a mutual municipal bond insurance company | Finance |
Wobi Insurance Agency Ltd.
 Wobi Insurance Agency Ltd. Insurance Brokers/ServicesFinance Engages in insurance agency business and online price comparison services for insurance products | Finance |
Removal Stars Ltd.
 Removal Stars Ltd. Internet Software/ServicesTechnology Services Operates an online platform that instantly generates prices to compare, read reviews and book online for home shifting services | Technology Services |
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