W. R. Berkley Corporation
MX ˙ BMV ˙ US0844231029
SecurityMX:WRB / W. R. Berkley Corporation
InstitutionM&t Bank Corp
Latest Disclosed Ownership15,689 shares
Latest Disclosed Value $ 1,039,867
M&t Bank Corp reports 6.00% decrease in ownership of WRB / W. R. Berkley Corporation

On May 12, 2026 - M&t Bank Corp filed a 13F-HR form disclosing ownership of 15,689 shares of W. R. Berkley Corporation (MX:WRB) valued at $1,039,867 USD as of March 31, 2026. The entity filed a previous 13F-HR/A on January 30, 2026 disclosing 16,690 shares of W. R. Berkley Corporation. This represents a change in shares of -6.00% during the quarter.

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)
2026-05-12 2026-03-31 13F BERKLEY W R COM 084423102 15,689 -1,001 -6.00 1,040 -11.20 0.0008
2026-01-30 2025-12-31 13F/A-1 BERKLEY W R COM 084423102 16,690 2,093 14.34 1,171 4.65 0.0038
2026-01-28 2025-12-31 13F BERKLEY W R COM 084423102 41,179 26,582 1,874 0.0011
2025-11-14 2025-09-30 13F BERKLEY W R COM 084423102 14,597 -6,376 -30.40 1,118 -27.40 0.0038
2025-08-13 2025-06-30 13F BERKLEY W R COM 084423102 20,973 2,081 11.02 1,540 14.58 0.0053
2025-04-30 2025-03-31 13F BERKLEY W R COM 084423102 18,892 1,329 7.57 1,344 30.87 0.0049
2025-02-06 2024-12-31 13F BERKLEY W R COM 084423102 17,563 1,295 7.96 1,028 11.39 0.0034
2024-11-19 2024-09-30 13F/A-1 BERKLEY W R COM 084423102 16,268 5,709 54.07 923 11.22 0.0030
2024-11-15 2024-09-30 13F AMERICAN HOMES 4 RENT CL A 084423102 57,243 46,684 2,631 0.0016
2024-07-31 2024-06-30 13F BERKLEY W R COM 084423102 10,559 1,351 14.67 830 1.84 0.0028
2024-05-07 2024-03-31 13F BERKLEY W R COM 084423102 9,208 -257 -2.72 814 21.67 0.0028
2024-02-06 2023-12-31 13F BERKLEY W R COM 084423102 9,465 234 2.53 669 14.16 0.0025
2023-11-02 2023-09-30 13F BERKLEY W R COM 084423102 9,231 -9,269 -50.10 586 -46.82 0.0023
2023-08-09 2023-06-30 13F BERKLEY W R COM 084423102 18,500 1,008 5.76 1,102 1.29 0.0041
2023-05-11 2023-03-31 13F BERKLEY W R COM 084423102 17,492 53 0.30 1,089 -14.06 0.0042
2023-02-13 2022-12-31 13F/A-1 BERKLEY W R COM 084423102 17,439 343 2.01 1,266 14.67 0.0051
2023-02-13 2022-12-31 13F BENTLEY SYS COM CL B 084423102 30,163 13,067 1,655 0.0067
2022-11-17 2022-09-30 13F/A-1 BERKLEY W R COM 084423102 17,096 -97 -0.56 1,104 -1.08 0.0049
2022-11-14 2022-09-30 13F BERKLEY W R COM 084423102 17,096 -97 1,104 0.0009
2022-08-05 2022-06-30 13F BERKLEY W R COM 084423102 17,193 736 4.47 1,116 1.82 0.0053
2022-05-09 2022-03-31 13F BERKLEY W R COM 084423102 16,457 5,331 47.91 1,096 19.65 0.0048
2022-02-07 2021-12-31 13F BERKLEY W R COM 084423102 11,126 377 3.51 916 16.69 0.0038
2021-10-28 2021-09-30 13F BERKLEY W R COM 084423102 10,749 -1,456 -11.93 785 -13.55 0.0035
2021-08-13 2021-06-30 13F BERKLEY W R COM 084423102 12,205 0 0.00 908 -1.20 0.0040
2021-05-06 2021-03-31 13F BERKLEY W R COM 084423102 12,205 -1,755 -12.57 919 -0.76 0.0040
2021-02-12 2020-12-31 13F BERKLEY W R COM 084423102 13,960 331 2.43 926 11.16 0.0041
2020-11-06 2020-09-30 13F BERKLEY W R COM 084423102 13,629 -591 -4.16 833 2.33 0.0041
2020-07-29 2020-06-30 13F BERKLEY W R COM 084423102 14,220 -631 -4.25 814 5.17 0.0044
2020-05-14 2020-03-31 13F BERKLEY W R COM 084423102 14,851 -166 -1.11 774 -25.43 0.0046
2020-02-07 2019-12-31 13F BERKLEY W R COM 084423102 15,017 7 0.05 1,038 -4.33 0.0049
2019-11-12 2019-09-30 13F BERKLEY W R COM 084423102 15,010 -125 -0.83 1,085 8.72 0.0054
2019-08-12 2019-06-30 13F BERKLEY W R COM 084423102 15,135 4,476 41.99 998 10.64 0.0052
2019-05-15 2019-03-31 13F BERKLEY W R COM 084423102 10,659 51 0.48 902 14.90 0.0047
2019-02-01 2018-12-31 13F W R BERKLEY COM 084423102 10,608 144 1.38 785 -6.10 0.0045
2018-11-09 2018-09-30 13F W R BERKLEY COM 084423102 10,464 -6,293 -37.55 836 -31.02 0.0042
2018-08-10 2018-06-30 13F W R BERKLEY COM 084423102 16,757 51 0.31 1,212 -0.16 0.0065
2018-05-04 2018-03-31 13F W R BERKLEY COM 084423102 16,706 -216 -1.28 1,214 0.00 0.0065
2018-02-06 2017-12-31 13F BERKLEY W R COM 084423102 16,922 195 1.17 1,214 8.68 0.0064
2017-11-13 2017-09-30 13F BERKLEY W R COM 084423102 16,727 247 1.50 1,117 -2.02 0.0061
2017-08-11 2017-06-30 13F BERKLEY W R COM 084423102 16,480 -280 -1.67 1,140 -3.72 0.0067
2017-05-10 2017-03-31 13F BERKLEY W R COM 084423102 16,760 527 3.25 1,184 9.73 0.0071
2017-02-14 2016-12-31 13F BERKLEY W R COM 084423102 16,233 -996 -5.78 1,079 8.33 0.0067
2016-11-04 2016-09-30 13F BERKLEY W R COM 084423102 17,229 -150 -0.86 996 -4.41 0.0063
2016-08-04 2016-06-30 13F BERKLEY W R COM 084423102 17,379 1,508 9.50 1,042 16.82 0.0070
2016-05-11 2016-03-31 13F BERKLEY W R COM 084423102 15,871 17 0.11 892 2.76 0.0060
2016-02-12 2015-12-31 13F BERKLEY W R COM 084423102 15,854 -977 -5.80 868 -5.24 0.0058
2015-11-13 2015-09-30 13F BERKLEY W R COM 084423102 16,831 1,722 11.40 916 16.69 0.0062
2015-08-14 2015-06-30 13F BERKLEY W R COM 084423102 15,109 -733 -4.63 785 -2.00 0.0047
2015-05-14 2015-03-31 13F BERKLEY W R COM 084423102 15,842 86 0.55 801 -0.87 0.0050
2015-02-12 2014-12-31 13F BERKLEY W R COM 084423102 15,756 52 0.33 808 7.59 0.0051
2014-11-14 2014-09-30 13F BERKLEY W R COM 084423102 15,704 15,704 751 0.0053
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.