White Mountains Insurance Group, Ltd.
US ˙ NYSE ˙ BMG9618E1075

SecurityWTM / White Mountains Insurance Group, Ltd.
InstitutionSignaturefd, Llc
Latest Disclosed Ownership75 shares
Latest Disclosed Value $ 164,772
Signaturefd, Llc reports 33.93% increase in ownership of WTM / White Mountains Insurance Group, Ltd.

On April 7, 2026 - Signaturefd, Llc filed a 13F-HR form disclosing ownership of 75 shares of White Mountains Insurance Group, Ltd. (US:WTM) valued at $164,772 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 20, 2026 disclosing 56 shares of White Mountains Insurance Group, Ltd.. This represents a change in shares of 33.93% during the quarter. The current value of the position is $154,886 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2026-04-07 2026-03-31 13F WHITE MTNS INS GROUP COM G9618E107 75 19 33.93 165 41.38 0.0025
2026-01-20 2025-12-31 13F WHITE MTNS INS GROUP COM G9618E107 56 3 5.66 116 31.82 0.0018
2025-10-21 2025-09-30 13F WHITE MTNS INS GROUP COM G9618E107 53 1 1.92 89 -5.38 0.0014
2025-07-16 2025-06-30 13F WHITE MTNS INS GROUP COM G9618E107 52 2 4.00 93 -3.12 0.0016
2025-05-02 2025-03-31 13F WHITE MTNS INS GROUP COM G9618E107 50 0 0.00 96 -1.03 0.0018
2025-02-10 2024-12-31 13F WHITE MTNS INS GROUP COM G9618E107 50 0 0.00 97 15.48 0.0018
2024-10-21 2024-09-30 13F WHITE MTNS INS GROUP COM G9618E107 50 -6 -10.71 85 -16.83 0.0016
2024-07-29 2024-06-30 13F WHITE MTNS INS GROUP COM G9618E107 56 -5 -8.20 102 -7.34 0.0021
2024-05-03 2024-03-31 13F WHITE MTNS INS GROUP COM G9618E107 61 5 8.93 109 29.76 0.0023
2024-02-01 2023-12-31 13F WHITE MTNS INS GROUP COM G9618E107 56 -10 -15.15 84 -14.29 0.0019
2023-11-03 2023-09-30 13F WHITE MTNS INS GROUP COM G9618E107 66 18 37.50 99 48.48 0.0026
2023-08-01 2023-06-30 13F WHITE MTNS INS GROUP COM G9618E107 48 -5 -9.43 67 -9.59 0.0017
2023-04-28 2023-03-31 13F WHITE MTNS INS GROUP COM G9618E107 53 -2 -3.64 73 -5.19 0.0020
2023-01-30 2022-12-31 13F WHITE MTNS INS GROUP COM G9618E107 55 8 17.02 78 26.23 0.0023
2022-11-08 2022-09-30 13F WHITE MTNS INS GROUP COM G9618E107 47 5 11.90 61 17.31 0.0021
2022-08-10 2022-06-30 13F WHITE MTNS INS GROUP COM G9618E107 42 10 31.25 52 44.44 0.0018
2022-05-02 2022-03-31 13F WHITE MTNS INS GROUP COM G9618E107 32 -7 -17.95 36 -10.00 0.0011
2022-01-25 2021-12-31 13F WHITE MTNS INS GROUP COM G9618E107 39 4 11.43 40 8.11 0.0012
2021-10-28 2021-09-30 13F WHITE MTNS INS GROUP COM G9618E107 35 6 20.69 37 12.12 0.0013
2021-07-26 2021-06-30 13F WHITE MTNS INS GROUP COM G9618E107 29 -13 -30.95 33 -29.79 0.0013
2021-04-30 2021-03-31 13F WHITE MTNS INS GROUP COM G9618E107 42 -6 -12.50 47 -2.08 0.0021
2021-02-11 2020-12-31 13F WHITE MTNS INS GROUP COM G9618E107 48 16 50.00 48 92.00 0.0023
2020-11-03 2020-09-30 13F WHITE MTNS INS GROUP COM G9618E107 32 -5 -13.51 25 -24.24 0.0013
2020-07-30 2020-06-30 13F WHITE MTNS INS GROUP COM G9618E107 37 -27 -42.19 33 -43.10 0.0020
2020-04-23 2020-03-31 13F WHITE MTNS INS GROUP COM G9618E107 64 -33 -34.02 58 -46.30 0.0050
2020-02-05 2019-12-31 13F WHITE MTNS INS GROUP COM G9618E107 97 16 19.75 108 24.14 0.0080
2019-10-16 2019-09-30 13F WHITE MTNS INS GROUP COM G9618E107 81 0 0.00 87 4.82 0.0071
2019-07-31 2019-06-30 13F WHITE MTNS INS GROUP COM G9618E107 81 -14 -14.74 83 -5.68 0.0072
2019-05-09 2019-03-31 13F WHITE MTNS INS GROUP COM G9618E107 95 -91 -48.92 88 -45.00 0.0075
2019-02-13 2018-12-31 13F WHITE MTNS INS GROUP COM G9618E107 186 -41 -18.06 160 -24.53 0.0149
2018-11-14 2018-09-30 13F WHITE MTNS INS GROUP COM G9618E107 227 -13 -5.42 212 -2.75 0.0215
2018-08-14 2018-06-30 13F WHITE MTNS INS GROUP COM G9618E107 240 105 77.78 218 96.40 0.0243
2018-05-08 2018-03-31 13F WHITE MTNS INS GROUP COM G9618E107 135 135 111 0.0130
2017-02-14 2016-12-31 13F WHITE MTNS INS GROUP COM G9618E107 0 -12 -100.00 0 -100.00
2016-11-14 2016-09-30 13F WHITE MTNS INS GROUP COM G9618E107 12 12 0.00 10 0.0015
2016-05-12 2016-03-31 13F WHITE MTNS INS GROUP COM G9618E107 0 -2 -100.00 0 -100.00
2016-01-22 2015-12-31 13F WHITE MTNS INS GROUP COM G9618E107 2 -9 -81.82 1 -87.50 0.0002
2015-10-23 2015-09-30 13F WHITE MTNS INS GROUP COM G9618E107 11 9 450.00 8 700.00 0.0018
2015-07-15 2015-06-30 13F WHITE MTNS INS GROUP COM G9618E107 2 -5 -71.43 1 -80.00 0.0002
2015-04-15 2015-03-31 13F WHITE MTNS INS GROUP COM G9618E107 7 -2 -22.22 5 -16.67 0.0012
2015-02-13 2014-12-31 13F WHITE MTNS INS GROUP COM G9618E107 9 0 0.00 6 0.00 0.0015
2014-11-13 2014-09-30 13F WHITE MTNS INS GROUP COM G9618E107 9 -8 -47.06 6 -40.00 0.0020
2014-08-14 2014-06-30 13F WHITE MTNS INS GROUP COM G9618E107 17 17 10 0.0035
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.