White Mountains Insurance 13F Portfolio Q4 2025

Latest Portfolio Value

$261.93 M

+28.90%

12/31/2025

Total Holdings

12/31/2025

Latest Report Date

Q4 2025

12/31/2025

Top 10 Concentration

100.00%

White Mountains Insurance Group LTD (CIK: 0000776867) is a financial institution headquartered at 23 South Main Street, Suite 3B, Hanover, New Hampshire 03755. The firm regularly files Form 13F with the U.S. Securities and Exchange Commission (SEC), disclosing its equity holdings and investment positions.

As of the latest reporting period (2025-12-31), the institution manages a portfolio valued at $261,929,551, comprising 2 distinct securities. Over its filing history, it has submitted 32 Form 13F reports.

To view the institution’s full SEC filing history:
🔗 View All SEC Filings

Top Buys

Q4 2025

1. SPY Spdr S&P 500 Etf Trust

+$30.69 M

Top Sells

Q4 2025

No sell transactions available for this period

Stocks/ETFs

+28.90%

$261.93 M 100.00%

Options

$0 0.00%

Debt

$0 0.00%

Other

$0 0.00%

Name	Shares	Market Value	Weight	Change	Activity
Mediaalpha MAX	17.86 M	$231.24 M	88.28%
Spdr S&P 500 Etf Trust ETF-SPY	45,000	$30.69 M	11.72%	▲ 45,000	New Buy

View Full List

White Mountains Insurance Group LTD's Portfolio

This portfolio view aggregates one or more SEC Form 13F filings submitted by White Mountains Insurance Group LTD each quarter. Holdings are organized into Stocks/ETFs, Options, Debt, and Other, with transaction markers indicating New Buy, Add, Reduce, No Change, or Sold Out. Reported anomalies are corrected where possible, and share counts are adjusted to reflect corporate actions such as stock splits. Since 2013, we have collected 32 quarters of portfolio data for this firm, providing a transparent record of institutional strategy over time.

Options Exposure History

CALL PUT

Report Date	Type	Underlying Shares	Notional Value	% Change

Report Date	Bought/Sold (Sh.)	% Change	Qtr. End Shares	Reported Price

Stocks ETFs

Name	Shares	Value	% of Portfolio	% Change
Loading holdings data...

Showing 1 to 20 of 0 entries

Show: per page

Note: Shares, Shares Change - split-adjusted.

CALL PUT

Type	Name	Shares	Value	% of Portfolio	% Change
Loading options data...

Showing 1 to 20 of 0 entries

Show: per page

Note: Shares, Shares Change - split-adjusted.

Name	Amount	Value	% of Portfolio	% Change
Loading debt data...

Showing 1 to 20 of 0 entries

Show: per page

Note: Shares, Shares Change - split-adjusted.

Name	Shares	Value	% of Portfolio	% Change
Loading other data...

Showing {0} to {1} of {2} entries

Show: per page

Note: Shares, Shares Change - split-adjusted.

White Mountains Insurance Group LTD Quarterly 13F Statistics

Discover detailed insights into White Mountains Insurance Group LTD’s SEC Form 13F filings, including:

Quarterly changes in holdings
Portfolio turnover
Asset allocation trends
Top 10 stock and ETF positions

This page provides a transparent view of institutional strategies based on official SEC disclosures, helping investors track long‑term shifts since 2013.

Quarter	Holdings	Total Value	Turnover Rate	Asset Allocation	Top 10 Stock & ETF Holdings

Showing 1 to 20 of 0 entries

Show: per page

White Mountains Insurance Group LTD's All 13F Filings

This section lists all SEC Form 13F filings submitted by White Mountains Insurance Group LTD. Since 2013, we have tracked a total of 0 filings submitted by this firm.

Form 13F must be filed within 45 days after the end of each calendar quarter and discloses the reporting manager, the securities held, their CUSIP numbers, the number of shares held at quarter-end, and the total reported market value.

Please note that the market value shown reflects reported holdings only and should not be considered a substitute for Assets Under Management (AUM), as cash positions are excluded.
Each filing entry includes a direct link to the original Form 13F document on the SEC’s EDGAR system .

Report For	Filed At	AUM	Holdings	Form Type	Source

Showing 1 to 20 of 0 entries

Show: per page

Insider Trading Activity (SEC Form 4)

This section tracks real-time insider transactions reported via SEC Form 4 filings. Unlike the quarterly 13F portfolio snapshots, these records reflect immediate buying and selling activity where the filer acts as a corporate insider. Use this data to spot timely market moves.

Date Top Line (Transaction Date): The date of the most recent insider transaction. Bottom Line (Filing Date): The date the transaction was filed with the SEC.	Value Total Value: The total monetary value of the transaction. (Shares × Price)	Shares Shares Traded: Number of shares bought or sold in this specific transaction. Adjusted for splits.	Position / Chg Top Line (Held): Total shares owned after the transaction. Bottom Line (Change %): The percentage change in holdings due to this trade.
Loading transactions...
No transactions found matching your filters.
Filed: Filed:	:	Shares Traded:	Held:

Showing to of results

Data Source & Methodology: This table is sourced exclusively from SEC Form 4 filings and is adjusted for stock splits. It reflects active insider trading decisions and does not include passive beneficial ownership reported in 13F or 13D/G filings.

White Mountains Insurance Group LTD 13F Filings, Portfolio & Analysis

White Mountains Insurance Group LTD — Portfolio Overview & Company Profile

Portfolio Summary (Q4 2025)

Top Buys

Top Sells

Asset Allocation

Sector Allocation (Stocks)

Top Stock & ETF Holdings (Q4 2025)

Historical Portfolio Charts

White Mountains Insurance Group LTD's Portfolio

White Mountains Insurance Group LTD Quarterly 13F Statistics

White Mountains Insurance Group LTD's All 13F Filings

Insider Trading Activity (SEC Form 4)