Berkshire Hathaway Inc.
MX ˙ BMV
SecurityMX:BRKB / Berkshire Hathaway Inc.
InstitutionGreat Diamond Partners, LLC
Latest Disclosed Ownership3,036 shares
Latest Disclosed Value $ 1,454,851
Great Diamond Partners, LLC reports 0.26% decrease in ownership of BRKB / Berkshire Hathaway Inc.

On May 12, 2026 - Great Diamond Partners, LLC filed a 13F-HR form disclosing ownership of 3,036 shares of Berkshire Hathaway Inc. (MX:BRKB) valued at $1,454,851 USD as of March 31, 2026.

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 3,036 -8 -0.26 1,455 -4.97 0.2800
2026-02-06 2025-12-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 3,044 9 0.30 1,530 0.33 0.2944
2025-10-20 2025-09-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 3,035 -3 -0.10 1,526 3.39 0.2959
2025-08-13 2025-06-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 3,038 56 1.88 1,476 -7.12 0.3117
2025-05-13 2025-03-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 2,982 73 2.51 1,588 20.49 0.4341
2025-01-23 2024-12-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 2,909 9 0.31 1,319 -1.20 0.3410
2024-10-25 2024-09-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 2,900 -83 -2.78 1,335 9.98 0.3392
2024-07-29 2024-06-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 2,983 -133 -4.27 1,213 -7.40 0.2852
2024-05-08 2024-03-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 3,116 -87 -2.72 1,310 14.71 0.3009
2024-02-07 2023-12-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 3,203 -23 -0.71 1,142 1.06 0.2815
2023-10-19 2023-09-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 3,226 275 9.32 1,130 12.33 0.3059
2023-07-17 2023-06-30 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 2,951 116 4.09 1,006 14.97 0.2657
2023-05-04 2023-03-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 2,835 -154 -5.15 875 -5.20 0.2535
2023-02-01 2022-12-31 13F BERKSHIRE HATHAWAY INC DEL CL B NEW 084670702 2,989 -173 -5.47 923 9.36 0.2842
2022-10-24 2022-09-30 13F BERKSHIRE HATHAWAY INC DEL CL B CL B NEW 084670702 3,162 4 0.13 844 -2.09 0.2884
2022-07-26 2022-06-30 13F BERKSHIRE HATHAWAY INC DEL CL B CL B NEW 084670702 3,158 67 2.17 862 -20.92 0.2866
2022-05-05 2022-03-31 13F BERKSHIRE HATHAWAY INC DEL CL B CL B NEW 084670702 3,091 61 2.01 1,090 20.44 0.3034
2022-01-26 2021-12-31 13F BERKSHIRE HATHAWAY INC DEL CL B CL B NEW 084670702 3,030 0 0.00 905 9.43 0.2330
2021-10-21 2021-09-30 13F BERKSHIRE HATHAWAY INC DEL CL B CL B NEW 084670702 3,030 293 10.71 827 8.82 0.2267
2021-07-26 2021-06-30 13F BERKSHIRE HATHAWAY INC DEL CL B CL B NEW 084670702 2,737 -61 -2.18 760 6.44 0.2149
2021-05-04 2021-03-31 13F BERKSHIRE HATHAWAY INC DEL CL B CL B NEW 084670702 2,798 40 1.45 714 11.74 0.2197
2021-01-26 2020-12-31 13F BERKSHIRE HATHAWAY INC DEL CL B CL B NEW 084670702 2,758 -559 -16.85 639 -9.49 0.2037
2020-10-19 2020-09-30 13F BERKSHIRE HATHAWAY INC DEL CL B CL B NEW 084670702 3,317 99 3.08 706 23.00 0.2591
2020-08-04 2020-06-30 13F BERKSHIRE HATHAWAY INC DEL CL B CL B NEW 084670702 3,218 -313 -8.86 574 -11.01 0.2376
2020-05-01 2020-03-31 13F BERKSHIRE HATHAWAY INC DEL CL B CL B NEW 084670702 3,531 360 11.35 645 -10.17 0.3320
2020-02-07 2019-12-31 13F BERKSHIRE HATHAWAY INC DEL CL B CL B NEW 084670702 3,171 3,171 718 0.2730
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.