White Mountains Insurance WTM Institutional Ownership

NYSE WTM

$2,205.11 -8.50 (-0.38%)

As of: Oct 21, 2026 · 3:59 PM EDT

Institutions by Trading Activity

352 Institutions

Increased 136 38.6%

Unchanged 75 21.3%

Reduced 141 40.1%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

89.06%

▼-0.30 pp QoQ

Shares Held by Institutions

2.17Mn

of 2.44Mn outstanding

▼-1.84% QoQ

Shares Outstanding

2.44Mn

266.92K held outside 13F filers

Institutional Investors

352

filed 13F for Jun 2026

▼-12 vs prior quarter

Net Shares Added (QoQ)

-40.74K

distributed since last quarter

Value of Holdings

$4.81Bn

reported market value

Shares Owned by Institutions

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Institutions

Accumulated Distributed

Latest quarter —

Net over range —

Accumulating quarters —

Ownership Summary

Updated Oct 11, 2026

White Mountains Insurance Group Ltd (NYSE:WTM) was held by 352 institutional investors that filed 13F reports for the quarter ended June 30, 2026.

These investors held 89.06% of outstanding shares in Q2 2026, down from 89.36% the quarter before.
Total shares held in White Mountains Insurance fell 1.84% versus Q1 2026, while the number of holders rose 10.00% versus Q2 2025.
Of the 352 holders of WTM in Q2 2026, 136 added to their positions, 141 reduced their stakes and 75 left their positions unchanged.
Combined, institutional investors held 2.17Mn shares of WTM as of Q2 2026, down 40.74K from the prior quarter and up 23.3K from a year earlier.
Dimensional Fund Advisors LP was the top holder of White Mountains Insurance as of June 30, 2026, with 158.95K shares, or 6.52% of shares outstanding.
The largest position increases in WTM for Q2 2026 were by American Century Companies Inc (+22.8K shares), Jeffrey L. Gendell (+21.43K shares), Gotham Asset Management, LLC (+8.89K shares), Qube Research & Technologies Ltd (+8.66K shares) and First Trust Advisors LP (+7.55K shares).
Among holders that kept a stake in White Mountains Insurance, the biggest sellers in Q2 2026 were Cooke & Bieler LP (-19.74K shares), Fiduciary Management Inc (-18.52K shares), Morgan Stanley (-12.43K shares), Raymond James Financial Inc (-9.12K shares) and UBS Asset Management Americas (-7.76K shares).
Per Business Quant, the top 10 investors in WTM for the quarter ended June 30, 2026 were Dimensional Fund Advisors LP (158.95K shares), Neuberger Berman Group LLC (119.14K shares), BlackRock, Inc. (117.85K shares), River Road Asset Management, LLC (115.88K shares), Vanguard Portfolio Management LLC (111.97K shares), Vanguard Capital Management LLC (107.48K shares), Fuller & Thaler Asset Management, Inc. (101.89K shares), Cooke & Bieler LP (85.12K shares), Wallace Capital Management Inc. (80.07K shares) and Fiduciary Management Inc (66.55K shares).

Form 13F Holdings

352 Institutional Holders

Report period 30 Jun, 2026

Total shares held 2.17Mn

Of outstanding 89.06%

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	DIMENSIONAL FUND ADVISORS LP	0000354204	158,954	6.52%	▲2,336	+1.49%	$329.58Mn
2	Neuberger Berman Group LLC	0001465109	119,141	4.88%	▼5,574	-4.47%	$247.03Mn
3	BlackRock, Inc.	0002012383	117,849	4.83%	▲4,521	+3.99%	$244.35Mn
4	River Road Asset Management, LLC	0001341401	115,880	4.75%	▼4,639	-3.85%	$240.26Mn
5	VANGUARD PORTFOLIO MANAGEMENT LLC	0002100121	111,969	4.59%	▼3,584	-3.10%	$232.16Mn
6	VANGUARD CAPITAL MANAGEMENT LLC	0002100119	107,479	4.41%	▼1,678	-1.54%	$222.85Mn
7	FULLER & THALER ASSET MANAGEMENT, INC.	0001082327	101,892	4.18%	▼2,669	-2.55%	$211.26Mn
8	COOKE & BIELER LP	0000024386	85,120	3.49%	▼19,737	-18.82%	$176.49Mn
9	Wallace Capital Management Inc.	0001459754	80,067	3.28%	▲1,272	+1.61%	$166.01Mn
10	FIDUCIARY MANAGEMENT INC /WI/	0000764532	66,550	2.73%	▼18,516	-21.77%	$137.98Mn
11	GENDELL JEFFREY L	0001056581	59,243	2.43%	▲21,429	+56.67%	$122.83Mn
12	Boston Partners	0001386060	55,569	2.28%	▼1,890	-3.29%	$115.28Mn
13	LONDON CO OF VIRGINIA	0001259887	54,025	2.21%	▼3,106	-5.44%	$112.08Mn
14	State Street Corp	0000093751	50,257	2.06%	▲1,099	+2.24%	$104.20Mn
15	GEODE CAPITAL MANAGEMENT, LLC	0001214717	49,412	2.03%	▲7,293	+17.32%	$102.47Mn
16	Morgan Stanley	0000895421	46,866	1.92%	▼12,429	-20.96%	$97.18Mn
17	REINHART PARTNERS, LLC.	0001080298	44,480	1.82%	▲7,106	+19.01%	$92.27Mn
18	T. Rowe Price Investment Management, Inc.	0001897612	34,237	1.40%	▼7,276	-17.53%	$70.99K
19	LORD, ABBETT & CO. LLC	0000728100	32,829	1.35%	▼281	-0.85%	$68.07K
20	AMERICAN CENTURY COMPANIES INC	0000748054	31,108	1.28%	▲22,800	+274.43%	$64.50Mn

Showing 1 to 20 of 352 holders