Security key
G9618E107
WHITE MOUNTAINS INSURANCE GROUP LTD - COMMON (WTM)
CUSIP: G9618E107
Q4 2025 13F Holders as of 31 Dec 2025
- Security type / class
- Equity / COMMON
- Total 13F shares
- 2,249,111
- Total 13F value
- $4,672,724,959
- Share change
- -82,314
- SEC-reported price per share
- $2078.03
- Number of holders
- 353
- Value change
- -$163,522,387
- Number of buys
- 150
- Number of sells
- 161
- Shares outstanding
- 2,481,286
Holder snapshot
6 signals
Security identity
Names, identifiers, and filing context for this profile.
1 source field
Report period
Q4 2025
Institutions
353
Top holders
10
WTM full security history
Ownership snapshot
Full 13F holder table
Newer quarter: Q1 2026
Previous quarter: Q3 2025
WHITE MOUNTAINS INSURANCE GROUP LTD SEC filings
WHITE MOUNTAINS INSURANCE GROUP LTD company facts
WHITE MOUNTAINS INSURANCE GROUP LTD 13D/G history
Broader feeds
Reporting periods
Holder history for CUSIP G9618E107
Recent filing periods:
Ownership snapshot
Top reported holders of WTM - WHITE MOUNTAINS INSURANCE GROUP LTD - COMMON (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
MORGAN STANLEY
Disclosed value leader
VANGUARD GROUP INC
Comparable rows
15/15
Latest evidence
30 Sep 2025
13F
13D/G
3/4/5
Lead comparable stake: 3%
13D/G row: MORGAN STANLEY
Showing 1-6 of 15 holder rows.
Quick read
MORGAN STANLEY leads the comparable SEC ownership view at 3%.
15 of 15 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens MORGAN STANLEY's linked filing trail.
Comparable ownership
Top 5
MORGAN STANLEY
3%
Steven Yi
0.02%
VANGUARD GROUP INC
10%
DIMENSIONAL FUND ADVISORS LP
6.3%
Neuberger Berman Group LLC
4.6%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-6 of 15 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| MORGAN STANLEY |
13F
13D/G
Company
|
3%
from 13D/G
|
$232,114,441
138,862 shares
|
— | 30 Sep 2025 |
| Steven Yi |
3/4/5
Director
|
0.02%
|
$930,352
525 shares
|
— | 22 May 2025 |
| VANGUARD GROUP INC |
13F
Company
|
10%
|
$412,872,126
247,004 shares
|
— | 30 Sep 2025 |
| DIMENSIONAL FUND ADVISORS LP |
13F
Company
|
6.3%
|
$262,792,354
157,217 shares
|
— | 30 Sep 2025 |
| Neuberger Berman Group LLC |
13F
Company
|
4.6%
|
$192,249,873
115,015 shares
|
— | 30 Sep 2025 |
| BlackRock, Inc. |
13F
Company
|
4.5%
|
$188,177,273
112,579 shares
|
— | 30 Sep 2025 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
13F holder rows
Institutional holders as of Q4 2025
Investor-level positions for this CUSIP, loaded as an interactive table.
Institutions
353
Shares
2,249,111
Rows available
353
| Investor | Option | Weight % | Change % | SEC-reported value | * Price | Shares | Share Change | Activity | Report Period |
|---|
* SEC-reported price is the security price as of the portfolio date and can indicate the last known price at which the security was still held. The marker flags a reported price that did not pass the local price check.
Compare Q4 2025 vs Q3 2025 Across Filers
Q3 2025 holders
337
Q4 2025 holders
353
Holder diff
16
| Investor | Q3 2025 Shares | Q4 2025 Shares | Share Diff | Share Chg % | Q3 2025 value | Q4 2025 value | Value change | Value Chg % |
|---|
Trend: ostatnie 8 kwartałów (+ wybrane okresy porównania).
Quarterly Holders Trend
Quarterly Value Trend
Quarterly Shares Trend