WHITE MOUNTAINS INSURANCE GROUP, LTD (WTM) capitalization
Current snapshot
Annual history
One row per fiscal year (10-K). Market cap uses split-adjusted closing price on the fiscal-year-end date × shares outstanding.
| Period | End | Market Cap |
|---|---|---|
| FY'25 | 2025-12-31 | $5.27B |
| FY'24 | 2024-12-31 | $4.93B |
| FY'23 | 2023-12-31 | $3.80B |
| FY'22 | 2022-12-31 | $4.00B |
| FY'21 | 2021-12-31 | $3.08B |
| FY'20 | 2020-12-31 | $3.08B |
| FY'19 | 2019-12-31 | $3.50B |
| FY'18 | 2018-12-31 | $2.87B |
| FY'17 | 2017-12-31 | $3.61B |
| FY'16 | 2016-12-31 | $4.14B |
| FY'15 | 2015-12-31 | $4.22B |
| FY'14 | 2014-12-31 | $3.80B |
| FY'13 | 2013-12-31 | $3.68B |
| FY'11 | 2012-12-31 | $3.45B |
| FY'11 | 2011-12-31 | $3.54B |
| FY'10 | 2010-12-31 | $2.84B |
| FY'10 | 2009-12-31 | $2.92B |
| FY'10 | 2008-12-31 | — |
Quarterly history
One row per quarter (10-Q and Q4 from 10-K). Market cap uses split-adjusted closing price on the quarter-end date × shares outstanding.
| Period | End | Market Cap |
|---|---|---|
| Q1'26 | 2026-03-31 | $5.38B |
| Q4'25 | 2025-12-31 | $5.15B |
| Q3'25 | 2025-09-30 | $4.25B |
| Q2'25 | 2025-06-30 | $4.56B |
| Q1'25 | 2025-03-31 | $4.89B |
| Q4'24 | 2024-12-31 | $5.00B |
| Q3'24 | 2024-09-30 | $4.30B |
| Q2'24 | 2024-06-30 | $4.60B |
| Q1'24 | 2024-03-31 | $4.54B |
| Q4'23 | 2023-12-31 | $3.85B |
| Q3'23 | 2023-09-30 | $3.77B |
| Q2'23 | 2023-06-30 | $3.51B |
| Q1'23 | 2023-03-31 | $3.50B |
| Q4'22 | 2022-12-31 | $3.64B |
| Q3'22 | 2022-09-30 | $3.72B |
| Q2'22 | 2022-06-30 | $3.66B |
| Q1'22 | 2022-03-31 | $3.38B |
| Q4'21 | 2021-12-31 | $3.06B |
| Q3'21 | 2021-09-30 | $3.26B |
| Q2'21 | 2021-06-30 | $3.52B |
| Q1'21 | 2021-03-31 | $3.42B |
| Q4'20 | 2020-12-31 | $3.10B |
| Q3'20 | 2020-09-30 | $2.38B |
| Q2'19 | 2020-06-30 | $2.72B |
| Q3'19 | 2020-03-31 | $2.86B |
| Q4'19 | 2019-12-31 | $3.55B |
| Q3'19 | 2019-09-30 | $3.39B |
| Q2'19 | 2019-06-30 | $3.21B |
| Q1'19 | 2019-03-31 | $2.91B |
| Q4'18 | 2018-12-31 | $2.72B |
| Q3'18 | 2018-09-30 | $2.94B |
| Q2'18 | 2018-06-30 | $3.07B |
| Q1'18 | 2018-03-31 | $3.05B |
| Q4'17 | 2017-12-31 | $3.19B |
| Q3'17 | 2017-09-30 | $3.64B |
| Q2'17 | 2017-06-30 | $3.92B |
| Q1'17 | 2017-03-31 | $3.97B |
| Q4'16 | 2016-12-31 | $3.82B |
| Q3'16 | 2016-09-30 | $3.99B |
| Q2'16 | 2016-06-30 | $4.24B |
| Q1'16 | 2016-03-31 | $4.40B |
| Q4'15 | 2015-12-31 | $4.09B |
| Q3'15 | 2015-09-30 | $4.40B |
| Q2'15 | 2015-06-30 | $3.87B |
| Q1'15 | 2015-03-31 | $4.05B |
| Q4'14 | 2014-12-31 | $3.77B |
| Q3'14 | 2014-09-30 | $3.84B |
| Q2'14 | 2014-06-30 | $3.70B |
| Q1'14 | 2014-03-31 | $3.66B |
| Q4'13 | 2013-12-31 | $3.73B |
| Q3'13 | 2013-09-30 | $3.45B |
| Q2'13 | 2013-06-30 | $3.50B |
| Q1'13 | 2013-03-31 | $3.51B |
| Q4'11 | 2012-12-31 | $3.24B |
| Q3'12 | 2012-09-30 | $3.33B |
| Q2'12 | 2012-06-30 | $3.41B |
| Q1'12 | 2012-03-31 | $3.69B |
| Q4'11 | 2011-12-31 | $3.44B |
| Q3'11 | 2011-09-30 | $3.18B |
| Q2'11 | 2011-06-30 | $3.31B |
| Q1'11 | 2011-03-31 | $2.90B |
| Q4'10 | 2010-12-31 | $2.75B |
| Q3'10 | 2010-09-30 | $2.60B |
| Q2'10 | 2010-06-30 | $2.81B |
| Q1'11 | 2010-03-31 | — |
| Q4'10 | 2009-12-31 | $2.95B |
| Q3'10 | 2009-09-30 | — |
| Q2'10 | 2009-06-30 | — |
Methodology
Every figure on this page traces back to SEC EDGAR XBRL company-facts filings (WTM CIK 0000776867), tagged with the us-gaap and dei taxonomies. Filing-anchored figures are rendered server-side: the market cap and enterprise value tiles use the split-adjusted close on the latest reported period-end × shares outstanding, so they reconcile with the equity / debt / cash figures from that same filing. The two price-anchored tiles (market cap + enterprise value) re-anchor on the most recent daily close in the browser when JavaScript is enabled; shares outstanding and debt / cash stay filing-anchored, so the EV bridge still uses the latest statement of financial position. Historical share prices come from our total-returns daily history (split-adjusted); historical market caps are calibrated against today's share count to correct for SEC retroactive split restatements.
For the exact XBRL concepts and formulas, see the methodology reference for net worth, debt, cash, market cap, enterprise value, net debt, shares outstanding, and the historical-market-cap calibration.