Berkshire Hathaway Inc.
MX ˙ BMV
SecurityMX:BRKB / Berkshire Hathaway Inc.
InstitutionM&t Bank Corp
Latest Disclosed Ownership279,146 shares
Latest Disclosed Value $ 133,766,764
M&t Bank Corp reports 0.99% decrease in ownership of BRKB / Berkshire Hathaway Inc.

On May 12, 2026 - M&t Bank Corp filed a 13F-HR form disclosing ownership of 279,146 shares of Berkshire Hathaway Inc. (MX:BRKB) valued at $133,766,764 USD as of March 31, 2026. The entity filed a previous 13F-HR/A on January 30, 2026 disclosing 281,923 shares of Berkshire Hathaway Inc.. This represents a change in shares of -0.99% 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 BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 279,146 -2,777 -0.99 133,767 -5.60 0.4578
2026-01-30 2025-12-31 13F/A-1 BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 281,923 20,824 7.98 141,709 7.96 0.4550
2026-01-28 2025-12-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 17,296 -243,803 1,037 0.0006
2025-11-14 2025-09-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 261,099 -31,007 -10.61 131,265 -7.49 0.4414
2025-08-13 2025-06-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 292,106 -4,798 -1.62 141,896 -10.26 0.4875
2025-04-30 2025-03-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 296,904 296,904 158,125 0.5760
2025-02-06 2024-12-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 0 -298,860 -100.00 0 -100.00
2024-11-19 2024-09-30 13F/A-1 BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 298,860 -874 -0.29 137,553 12.81 0.4523
2024-11-15 2024-09-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 298,860 -874 137,553 0.0827
2024-07-31 2024-06-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 299,734 -2,898 -0.96 121,932 -4.19 0.4161
2024-05-07 2024-03-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 302,632 5,257 1.77 127,263 19.99 0.4428
2024-02-06 2023-12-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 297,375 -13,021 -4.19 106,062 -2.46 0.3896
2023-11-02 2023-09-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 310,396 -18,747 -5.70 108,732 -3.12 0.4338
2023-08-09 2023-06-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 329,143 -58,122 -15.01 112,238 -6.14 0.4190
2023-05-11 2023-03-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 387,265 -13,191 -3.29 119,576 -3.33 0.4630
2023-02-13 2022-12-31 13F/A-1 BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 400,456 51,059 14.61 123,701 32.59 0.4976
2023-02-13 2022-12-31 13F BERKSHIRE HATHAWAY INC DEL CL A 084670702 400,308 50,911 132,086 0.5313
2022-11-17 2022-09-30 13F/A-1 BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 349,397 -18,660 -5.07 93,296 17.34 0.4144
2022-11-14 2022-09-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 349,397 -18,660 93,296 0.0796
2022-08-05 2022-06-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 368,057 100,145 37.38 79,509 -15.91 0.3745
2022-05-09 2022-03-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 267,912 -24,593 -8.41 94,548 8.10 0.4176
2022-02-07 2021-12-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 292,505 -9,232 -3.06 87,460 6.20 0.3674
2021-10-28 2021-09-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 301,737 -6,790 -2.20 82,356 -3.95 0.3708
2021-08-13 2021-06-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 308,527 -35,328 -10.27 85,746 -2.39 0.3765
2021-05-06 2021-03-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 343,855 -94,872 -21.62 87,842 -13.65 0.3791
2021-02-12 2020-12-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 438,727 -4,575 -1.03 101,729 7.77 0.4463
2020-11-06 2020-09-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 443,302 -9,880 -2.18 94,397 16.69 0.4634
2020-07-29 2020-06-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 453,182 -19,722 -4.17 80,897 -6.44 0.4336
2020-05-14 2020-03-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 472,904 14,626 3.19 86,461 -9.30 0.5114
2019-11-12 2019-09-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 458,278 12,644 2.84 95,331 0.35 0.4756
2019-08-12 2019-06-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 445,634 -493 -0.11 94,996 6.00 0.4962
2019-05-15 2019-03-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 446,127 32,548 7.87 89,623 6.13 0.4686
2019-02-01 2018-12-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 413,579 -4,993 -1.19 84,445 -5.78 0.4847
2018-11-09 2018-09-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 418,572 -7,726 -1.81 89,621 12.63 0.4483
2018-08-10 2018-06-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 426,298 2,076 0.49 79,570 -5.97 0.4283
2018-05-04 2018-03-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 424,222 1,955 0.46 84,623 1.10 0.4546
2018-02-06 2017-12-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 422,267 4,031 0.96 83,702 9.17 0.4386
2017-11-13 2017-09-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 418,236 10,327 2.53 76,673 10.98 0.4160
2017-08-11 2017-06-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 407,909 27,789 7.31 69,087 9.04 0.4079
2017-05-10 2017-03-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 380,120 -6,951 -1.80 63,357 0.43 0.3826
2017-02-14 2016-12-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 387,071 7,415 1.95 63,084 15.01 0.3930
2016-11-04 2016-09-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 379,656 -792 -0.21 54,851 -0.42 0.3495
2016-08-04 2016-06-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 380,448 -3,378 -0.88 55,085 1.15 0.3707
2016-05-11 2016-03-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 383,826 -30,136 -7.28 54,457 -0.37 0.3686
2016-02-12 2015-12-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 413,962 5,736 1.41 54,658 2.68 0.3628
2015-11-13 2015-09-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 408,226 81,322 24.88 53,232 19.64 0.3627
2015-08-14 2015-06-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 326,904 -15,775 -4.60 44,494 -10.03 0.2684
2015-05-14 2015-03-31 13F BERKSHIRE HATHAWAY COM 084670702 342,679 7,077 2.11 49,456 -1.85 0.3085
2015-02-12 2014-12-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 335,602 13,272 4.12 50,390 13.17 0.3154
2014-11-14 2014-09-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 322,330 285,048 764.57 44,527 843.77 0.3120
2014-08-13 2014-06-30 13F BERKSHIRE HATHAWAY INC DEL CL COMMON 084670702 37,282 -6,113 -14.09 4,718 -13.00 0.1973
2014-05-14 2014-03-31 13F BERKSHIRE HATHAWAY INC DEL CL COMMON STOCK 084670702 43,395 -3,365 -7.20 5,423 -2.18 0.2250
2014-02-12 2013-12-31 13F BERKSHIRE HATHAWAY INC DEL CL COMMON STOCK 084670702 46,760 -3,375 -6.73 5,544 -2.58 0.2322
2013-11-13 2013-09-30 13F BERKSHIRE HATHAWAY INC DEL CL COMMON STOCK 084670702 50,135 -4,317 -7.93 5,691 -6.61 0.2715
2013-07-30 2013-06-30 13F BERKSHIRE HATHAWAY INC DEL CL COMMON STOCK 084670702 54,452 54,452 6,094 0.2955
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.