Vault-13

WHITE MTNS INS GROUP LTD WTM

COM · Common Stock · CUSIP G9618E107

326 institutional holders +3 vs Q1 2025
2,295,2862.3m shares reported held*
89.1% of all shares outstanding*
$4.1bnreported value*
30 new 103 added 112 reduced 26 sold out net bought ≈ $23.4m (+13.0k shares)

* Summed across managers. Shares that two managers' reports both contain – a subsidiary's holdings that its parent's report includes too, or a sub-adviser's in its client's – are counted once ($48.5m this quarter). Holder counts are more reliable. Shares outstanding: 2.6m as of 2025-08-01, from the company's own SEC filing; the percentage can still exceed 100%: lent-out shares are counted by the lender and the buyer, and some reports overlap without saying so. Implied quarter-end price ≈ $1795.16.

Trends to Q2 2025

Institutional holders

Managers reporting a position, each quarter

0200400Q3 22: 253Q4 22: 264Q1 23: 262Q2 23: 258Q3 23: 272Q4 23: 295Q1 24: 303Q2 24: 306Q3 24: 304Q4 24: 325Q1 25: 323Q2 25: 326326Q3 22Q2 23Q1 24Q4 24Q2 25
Numbers
QuarterHolders
Q3 2022253
Q4 2022264
Q1 2023262
Q2 2023258
Q3 2023272
Q4 2023295
Q1 2024303
Q2 2024306
Q3 2024304
Q4 2024325
Q1 2025323
Q2 2025326

Buyers vs sellers

Managers adding to or starting a position, vs cutting or selling out

Bought or addedCut or sold out
2000200Q3 23: 110 bought or addedQ3 23: 100 cut or sold outQ4 23: 114 bought or addedQ4 23: 116 cut or sold outQ4 23Q1 24: 129 bought or addedQ1 24: 121 cut or sold outQ2 24: 132 bought or addedQ2 24: 113 cut or sold outQ2 24Q3 24: 132 bought or addedQ3 24: 108 cut or sold outQ4 24: 140 bought or addedQ4 24: 97 cut or sold outQ4 24Q1 25: 124 bought or addedQ1 25: 133 cut or sold outQ2 25: 133 bought or addedQ2 25: 138 cut or sold outQ2 25
Numbers
QuarterBought or addedCut or sold out
Q3 2023110100
Q4 2023114116
Q1 2024129121
Q2 2024132113
Q3 2024132108
Q4 202414097
Q1 2025124133
Q2 2025133138

Biggest buyers

NEUBERGER BERMAN GROUP LLC Added +26,835+26.8k
COOKE & BIELER LP Added +22,129+22.1k
BRADLEY FOSTER & SARGENT INC/CT New +5,522+5.5k
JANE STREET GROUP, LLC Added +5,493+5.5k
HRT FINANCIAL LP New +5,087+5.1k
Allspring Global Investments Holdings, LLC Added +4,728+4.7k
Edgestream Partners, L.P. Added +4,269+4.3k
Boston Partners Added +4,158+4.2k
ROYAL BANK OF CANADA Added +3,098+3.1k
GOLDMAN SACHS GROUP INC Added +2,626+2.6k

Biggest sellers

FIRST TRUST ADVISORS LP Reduced -17,255-17.3k
Select Equity Group, L.P. Reduced -10,127-10.1k
FULLER & THALER ASSET MANAGEMENT, INC. Reduced -9,108-9.1k
Alaska Permanent Fund Corp Sold out -5,902-5.9k
MORGAN STANLEY Reduced -5,567-5.6k
ROYCE & ASSOCIATES LP Reduced -4,985-5.0k
Nuveen, LLC Reduced -4,312-4.3k
BlackRock, Inc. Reduced -3,641-3.6k
Bank of New York Mellon Corp Reduced -1,710-1.7k
BANK OF AMERICA CORP /DE/ Reduced -1,646-1.6k

Major shareholders (over 5%)

Anyone who owns more than 5% of a class of the company's shares has to say so: on Schedule 13D if they may try to influence or control the company, on 13G if they're a passive investor, and update it as the stake changes. Each holder's latest filing, from 19 Dec 2024 on; percentages are of the share class, as the holder worked them out.

HolderStakeChangeShares Last filed
VANGUARD CAPITAL MANAGEMENT LLC 13G · institution new · filed 2026-04-30 5.2% new 128.0k≈ $265.4m 2026-04-30

Fell to 5% or below in the last year: Neuberger Berman Group LLC (4.9%, 2026-05-07), VANGUARD GROUP INC (0.0%, 2026-03-27; now reported by VANGUARD CAPITAL MANAGEMENT LLC), MORGAN STANLEY (3.0%, 2026-02-12)

Insider purchases and sales in Q2 2025

Shares bought or sold by the company's own officers, directors and 10% owners, in the open market or privately, as they reported to the SEC on Form 4 (due within two business days of the trade). Grants, option exercises, shares withheld for tax and gifts aren't included.

Officers and directors buying vs selling

Number of people, by quarter (10% owners not included)

BuyingSelling
101Q3 23: 0 buyingQ3 23: 0 sellingQ4 23: 1 buyingQ4 23: 0 sellingQ4 23Q1 24: 0 buyingQ1 24: 0 sellingQ2 24: 0 buyingQ2 24: 0 sellingQ2 24Q3 24: 0 buyingQ3 24: 0 sellingQ4 24: 0 buyingQ4 24: 0 sellingQ4 24Q1 25: 0 buyingQ1 25: 0 sellingQ2 25: 0 buyingQ2 25: 0 sellingQ2 25
Numbers
QuarterBuyingBoughtSellingSoldSold under a plan
Q3 20230—0——
Q4 20231$1.5m0——
Q1 20240—0——
Q2 20240—0——
Q3 20240—0——
Q4 20240—0——
Q1 20250—0——
Q2 20250—0——

None reported in Q2 2025.

Holders, Q2 2025

#ManagerLocationShares Value% of their portfolioChangeShares change
1 VANGUARD GROUP INC 0.01% of their portfolio Valley Forge, PA 249,170249.2k $447.4m $447.4m 0.01% Reduced -946 -946
2 MORGAN STANLEY 0.02% of their portfolio NEW YORK, NY 165,064165.1k $296.4m $296.4m 0.02% Reduced -5.6k -5,567
3 DIMENSIONAL FUND ADVISORS LP 0.06% of their portfolio AUSTIN, TX 155,753155.8k $279.7m $279.7m 0.06% Reduced -864 -864
4 BlackRock, Inc. 0.00% of their portfolio New York, NY 113,158113.2k $203.2m $203.2m 0.00% Reduced -3.6k -3,641
5 River Road Asset Management, LLC 2.49% of their portfolio LOUISVILLE, KY 109,892109.9k $196.5m $196.5m 2.49% Added +227 +227
6 FULLER & THALER ASSET MANAGEMENT, INC. 0.66% of their portfolio SAN MATEO, CA 100,984101.0k $181.3m $181.3m 0.66% Reduced -9.1k -9,108
7 Boston Partners 0.18% of their portfolio BOSTON, MA 89,39489.4k $160.5m $160.5m 0.18% Added +4.2k +4,158
8 NEUBERGER BERMAN GROUP LLC 0.12% of their portfolio NEW YORK, NY 83,69983.7k $150.3m $150.3m 0.12% Added +26.8k +26,835
9 Wallace Capital Management Inc. 19.34% of their portfolio DALLAS, TX 79,03679.0k $141.9m $141.9m 19.34% Reduced -895 -895
10 COOKE & BIELER LP 1.38% of their portfolio PHILADELPHIA, PA 76,78176.8k $137.9m $137.9m 1.38% Added +22.1k +22,129
11 FIDUCIARY MANAGEMENT INC /WI/ 1.23% of their portfolio MILWAUKEE, WI 71,47871.5k $128.4m $128.4m 1.23% Reduced -317 -317
12 LONDON CO OF VIRGINIA 0.70% of their portfolio RICHMOND, VA 68,77068.8k $123.5m $123.5m 0.70% Reduced -388 -388
13 T. Rowe Price Investment Management, Inc. 0.07% of their portfolio BALTIMORE, MD 62,94162.9k $113.0m $113.0m 0.07% Added +475 +475
14 STATE STREET CORP 0.00% of their portfolio BOSTON, MA 57,24157.2k $102.8m $102.8m 0.00% Added +2.3k +2,297
15 GEODE CAPITAL MANAGEMENT, LLC 0.01% of their portfolio BOSTON, MA 42,52942.5k $76.4m $76.4m 0.01% Added +343 +343
16 REINHART PARTNERS, LLC. 2.56% of their portfolio MEQUON, WI 41,69441.7k $74.9m $74.9m 2.56% Reduced -784 -784
17 BANK OF AMERICA CORP /DE/ 0.01% of their portfolio CHARLOTTE, NC 39,40939.4k $70.8m $70.8m 0.01% Reduced -1.6k -1,646
18 LORD, ABBETT & CO. LLC 0.19% of their portfolio JERSEY CITY, NJ 32,22732.2k $57.9m $57.9m 0.19% Reduced -624 -624
19 RAYMOND JAMES FINANCIAL INC 0.02% of their portfolio ST. PETERSBURG, FL 30,67730.7k $55.1m $55.1m 0.02% Reduced -1.0k -1,047
20 NORGES BANK 0.01% of their portfolio OSLO, Q8 30,49430.5k $54.8m $54.8m 0.01% Reduced -476 -476
21 Allspring Global Investments Holdings, LLC 0.09% of their portfolio CHARLOTTE, NC 29,58529.6k $53.0m $53.0m 0.09% Added +4.7k +4,728
22 Cannell & Spears LLC 1.03% of their portfolio NEW YORK, NY 28,34728.3k $50.9m $50.9m 1.03% Reduced -321 -321
23 WELLINGTON MANAGEMENT GROUP LLP 0.01% of their portfolio Boston, MA 24,65124.7k $44.3m $44.3m 0.01% Reduced -787 -787
24 CHARLES SCHWAB INVESTMENT MANAGEMENT INC 0.01% of their portfolio SAN FRANCISCO, CA 24,18324.2k $43.4m $43.4m 0.01% Reduced -523 -523
25 Mraz, Amerine & Associates, Inc. 6.21% of their portfolio Modesto, CA 21,57621.6k $38.7m $38.7m 6.21% Added +548 +548
26 SOUTHEASTERN ASSET MANAGEMENT INC/TN/ 1.91% of their portfolio MEMPHIS, TN 21,09421.1k $37.9m $37.9m 1.91% Added +2.6k +2,610
27 BROWN ADVISORY INC 0.05% of their portfolio BALTIMORE, MD 20,85420.9k $37.4m $37.4m 0.05% Reduced -1.2k -1,222
28 Select Equity Group, L.P. 0.14% of their portfolio NEW YORK, NY 17,87217.9k $32.1m $32.1m 0.14% Reduced -10.1k -10,127
29 Robeco Institutional Asset Management B.V. 0.05% of their portfolio ROTTERDAM, P7 17,82217.8k $32.0m $32.0m 0.05% Reduced -1.3k -1,332
30 VICTORY CAPITAL MANAGEMENT INC 0.02% of their portfolio San Antonio, TX 17,64017.6k $31.7m $31.7m 0.02% Added +1.5k +1,549
31 ENVESTNET ASSET MANAGEMENT INC 0.01% of their portfolio Berwyn, PA 17,51117.5k $31.4m $31.4m 0.01% Added +242 +242
32 NORTHERN TRUST CORP 0.00% of their portfolio CHICAGO, IL 17,40517.4k $31.3m $31.3m 0.00% Reduced -817 -817
33 ELKHORN PARTNERS LIMITED PARTNERSHIP 19.45% of their portfolio OMAHA, NE 14,90014.9k $26.8m $26.8m 19.45% Reduced -5 -5
34 WCM INVESTMENT MANAGEMENT, LLC 0.05% of their portfolio LAGUNA BEACH, CA 13,09713.1k $23.4m $23.4m 0.05% Reduced -148 -148
35 UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC 0.00% of their portfolio NEW YORK, NY 12,27612.3k $22.0m $22.0m 0.00% Added +989 +989
36 SPEECE THORSON CAPITAL GROUP INC 4.16% of their portfolio MINNETONKA, MN 11,38311.4k $20.4m $20.4m 4.16% Added +224 +224
37 HORIZON KINETICS ASSET MANAGEMENT LLC 0.23% of their portfolio NEW YORK, NY 10,97111.0k $19.7m $19.7m 0.23% Reduced -374 -374
38 Bank of New York Mellon Corp 0.00% of their portfolio NEW YORK, NY 10,86010.9k $19.5m $19.5m 0.00% Reduced -1.7k -1,710
39 California Public Employees Retirement System 0.01% of their portfolio Sacramento, CA 10,39410.4k $18.7m $18.7m 0.01% Reduced -1.1k -1,141
40 WELLS FARGO & COMPANY/MN 0.00% of their portfolio SAN FRANCISCO, CA 9,5879.6k $17.2m $17.2m 0.00% Added +237 +237
41 THOMPSON SIEGEL & WALMSLEY LLC 0.25% of their portfolio RICHMOND, VA 8,3058.3k $14.9m $14.9m 0.25% Reduced -12 -12
42 GW&K Investment Management, LLC 0.13% of their portfolio BOSTON, MA 8,2728.3k $14.9m $14.9m 0.13% Reduced -195 -195
43 AQR CAPITAL MANAGEMENT LLC 0.01% of their portfolio Greenwich, CT 8,0848.1k $14.4m $14.4m 0.01% Reduced -408 -408
44 Edgestream Partners, L.P. 0.39% of their portfolio Princeton, NJ 7,8097.8k $14.0m $14.0m 0.39% Added +4.3k +4,269
45 Perpetual Ltd 0.16% of their portfolio SYDNEY, NEW SOUTH WALES, C3 7,7277.7k $13.9m $13.9m 0.16% Unchanged
46 GOLDMAN SACHS GROUP INC 0.00% of their portfolio NEW YORK, NY 6,8856.9k $12.4m $12.4m 0.00% Added +2.6k +2,626
47 HOTCHKIS & WILEY CAPITAL MANAGEMENT LLC 0.04% of their portfolio Los Angeles, CA 6,8696.9k $12.3m $12.3m 0.04% Reduced -24 -24
48 ROYCE & ASSOCIATES LP 0.12% of their portfolio New York, NY 6,6036.6k $11.9m $11.9m 0.12% Reduced -5.0k -4,985
49 AMERICAN CENTURY COMPANIES INC 0.01% of their portfolio KANSAS CITY, MO 6,3656.4k $11.4m $11.4m 0.01% Reduced -671 -671
50 JANE STREET GROUP, LLC 0.02% of their portfolio NEW YORK, NY 6,0716.1k $10.9m $10.9m 0.02% Added +5.5k +5,493
51 FIRST TRUST ADVISORS LP 0.01% of their portfolio Wheaton, IL 5,6725.7k $10.2m $10.2m 0.01% Reduced -17.3k -17,255
52 BRADLEY FOSTER & SARGENT INC/CT 0.16% of their portfolio HARTFORD, CT 5,5225.5k $9.9m $9.9m 0.16% New
53 Phocas Financial Corp. 1.39% of their portfolio ALAMEDA, CA 5,3925.4k $9.7m $9.7m 1.39% Added +1 +1
54 Williams Jones Wealth Management, LLC. 0.11% of their portfolio NEW YORK, NY 5,1935.2k $9.3m $9.3m 0.11% Unchanged
55 HRT FINANCIAL LP 0.05% of their portfolio NEW YORK, NY 5,0875.1k $9.1m $9.1m 0.05% New
56 UBS Group AG 0.00% of their portfolio ZURICH, V8 5,0125.0k $9.0m $9.0m 0.00% Added +1.5k +1,494
57 Swiss National Bank 0.01% of their portfolio ZURICH, V8 4,9464.9k $8.9m $8.9m 0.01% Unchanged
58 SEI INVESTMENTS CO 0.01% of their portfolio OAKS, PA 4,9054.9k $8.8m $8.8m 0.01% Added +805 +805
59 ROYAL BANK OF CANADA 0.00% of their portfolio TORONTO, A6 4,3804.4k $7.9m $7.9m 0.00% Added +3.1k +3,098
60 Legal & General Group Plc 0.00% of their portfolio London, X0 4,3094.3k $7.7m $7.7m 0.00% Added +179 +179
61 Quantinno Capital Management LP 0.03% of their portfolio NEW YORK, NY 4,2904.3k $7.7m $7.7m 0.03% Reduced -316 -316
62 RHUMBLINE ADVISERS 0.01% of their portfolio BOSTON, MA 4,2804.3k $7.7m $7.7m 0.01% Reduced -192 -192
63 PROSPECTOR PARTNERS LLC 0.85% of their portfolio GUILFORD, CT 4,0764.1k $7.3m $7.3m 0.85% Added +221 +221
64 Invesco Ltd. 0.00% of their portfolio ATLANTA, GA 3,6463.6k $6.5m $6.5m 0.00% Reduced -374 -374
65 Brandywine Global Investment Management, LLC 0.04% of their portfolio PHILADELPHIA, PA 3,5263.5k $6.3m $6.3m 0.04% Reduced -100 -100
66 AMERIPRISE FINANCIAL INC 0.00% of their portfolio MINNEAPOLIS, MN 3,4823.5k $6.3m $6.3m 0.00% Reduced -50 -50
67 Nuveen, LLC 0.00% of their portfolio CHARLOTTE, NC 3,4583.5k $6.2m $6.2m 0.00% Reduced -4.3k -4,312
68 BARCLAYS PLC 0.00% of their portfolio LONDON, X0 3,3833.4k $6.1m $6.1m 0.00% Added +88 +88
69 LEE DANNER & BASS INC 0.44% of their portfolio NASHVILLE, TN 3,1483.1k $5.7m $5.7m 0.44% Unchanged
70 HARBOR CAPITAL ADVISORS, INC. 0.22% of their portfolio CHICAGO, IL 2,9763.0k $5.3m $5.3m 0.22% Reduced -82 -82
71 Creative Planning 0.00% of their portfolio OVERLAND PARK, KS 2,8422.8k $5.1m $5.1m 0.00% Added +152 +152
72 MML INVESTORS SERVICES, LLC 0.01% of their portfolio SPRINGFIELD, MA 2,7342.7k $4.9m $4.9m 0.01% Added +160 +160
73 STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM 0.01% of their portfolio TALLAHASSEE, FL 2,6132.6k $4.7m $4.7m 0.01% Reduced -379 -379
74 NEW YORK STATE COMMON RETIREMENT FUND 0.01% of their portfolio ALBANY, NY 2,5192.5k $4.5m $4.5m 0.01% Reduced -204 -204
75 D. E. Shaw & Co., Inc. 0.00% of their portfolio New York, NY 2,4362.4k $4.4m $4.4m 0.00% Added +78 +78
76 CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM 0.00% of their portfolio WEST SACRAMENTO, CA 2,3722.4k $4.3m $4.3m 0.00% Unchanged
77 JPMORGAN CHASE & CO 0.00% of their portfolio NEW YORK, NY 2,3232.3k $4.2m $4.2m 0.00% Added +337 +337
78 DAVENPORT & Co LLC 0.02% of their portfolio RICHMOND, VA 2,1732.2k $3.9m $3.9m 0.02% Unchanged
79 Forum Financial Management, LP 0.06% of their portfolio LOMBARD, IL 2,0162.0k $3.6m $3.6m 0.06% Added +353 +353
80 LPL Financial LLC 0.00% of their portfolio FORT MILL, SC 1,9852.0k $3.6m $3.6m 0.00% Added +115 +115
81 Cerity Partners LLC 0.01% of their portfolio NEW YORK, NY 1,9001.9k $3.4m $3.4m 0.01% Added +4 +4
82 PARSONS CAPITAL MANAGEMENT INC/RI 0.21% of their portfolio PROVIDENCE, RI 1,8921.9k $3.4m $3.4m 0.21% Added +384 +384
83 Qube Research & Technologies Ltd 0.00% of their portfolio LONDON, X0 1,7921.8k $3.2m $3.2m 0.00% Added +517 +517
84 PRICE T ROWE ASSOCIATES INC /MD/ 0.00% of their portfolio BALTIMORE, MD 1,7511.8k $3.1m $3.1m 0.00% Added +79 +79
85 TD Asset Management Inc 0.00% of their portfolio Toronto, A6 1,6181.6k $2.9m $2.9m 0.00% Added +26 +26
86 Focus Partners Wealth 0.01% of their portfolio ST LOUIS, MO 1,5961.6k $2.9m $2.9m 0.01% Added +249 +249
87 STRS OHIO 0.01% of their portfolio COLUMBUS, OH 1,5751.6k $2.8m $2.8m 0.01% Added +430 +430
88 HighTower Advisors, LLC 0.00% of their portfolio CHICAGO, IL 1,4641.5k $2.6m $2.6m 0.00% Reduced -2 -2
89 MILLENNIUM MANAGEMENT LLC 0.00% of their portfolio NEW YORK, NY 1,3921.4k $2.5m $2.5m 0.00% Added +436 +436
90 OPPENHEIMER ASSET MANAGEMENT INC. 0.03% of their portfolio NEW YORK, NY 1,3631.4k $2.4m $2.4m 0.03% Added +28 +28
91 CITIGROUP INC 0.00% of their portfolio NEW YORK, NY 1,3621.4k $2.4m $2.4m 0.00% Added +494 +494
92 STIFEL FINANCIAL CORP 0.00% of their portfolio ST. LOUIS, MO 1,3441.3k $2.4m $2.4m 0.00% Reduced -61 -61
93 AGF MANAGEMENT LTD 0.01% of their portfolio TORONTO, A6 1,3321.3k $2.4m $2.4m 0.01% Added +56 +56
94 Main Street Financial Solutions, LLC 0.17% of their portfolio NEWTOWN, PA 1,2931.3k $2.3m $2.3m 0.17% Added +32 +32
95 TRUIST FINANCIAL CORP 0.00% of their portfolio CHARLOTTE, NC 1,2401.2k $2.2m $2.2m 0.00% Reduced -129 -129
96 TEACHERS RETIREMENT SYSTEM OF THE STATE OF KENTUCKY 0.02% of their portfolio FRANKFORT, KY 1,2081.2k $2.2m $2.2m 0.02% Unchanged
97 1834 INVESTMENT ADVISORS CO 0.27% of their portfolio Milwaukee, WI 1,1761.2k $2.1m $2.1m 0.27% Unchanged
98 CITADEL ADVISORS LLC 0.00% of their portfolio MIAMI, FL 1,1711.2k $2.1m $2.1m 0.00% Reduced -5 -5
99 PECAUT & CO. 0.70% of their portfolio SIOUX CITY, IA 1,1671.2k $2.1m $2.1m 0.70% Unchanged
100 LEUTHOLD GROUP, LLC 0.25% of their portfolio MINNEAPOLIS, MN 1,1651.2k $2.1m $2.1m 0.25% Reduced -23 -23