Berkshire Hathaway Inc.
MX ˙ BMV
SecurityMX:BRKB / Berkshire Hathaway Inc.
InstitutionCorundum Group, Inc.
Latest Disclosed Ownership2,552 shares
Latest Disclosed Value $ 1,222,918
Corundum Group, Inc. reports 1.47% increase in ownership of BRKB / Berkshire Hathaway Inc.

On April 20, 2026 - Corundum Group, Inc. filed a 13F-HR form disclosing ownership of 2,552 shares of Berkshire Hathaway Inc. (MX:BRKB) valued at $1,222,918 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 12, 2026 disclosing 2,515 shares of Berkshire Hathaway Inc.. This represents a change in shares of 1.47% 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)
2026-04-20 2026-03-31 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 2,552 37 1.47 1,223 -3.32 0.4087
2026-01-12 2025-12-31 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 2,515 -94 -3.60 1,264 -3.59 0.4242
2025-10-24 2025-09-30 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 2,609 5 0.19 1,312 3.72 0.5389
2025-07-21 2025-06-30 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 2,604 516 24.71 1,265 13.67 0.5593
2025-04-23 2025-03-31 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 2,088 -1,559 -42.75 1,112 -32.73 0.5333
2025-01-16 2024-12-31 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 3,647 2,088 133.93 1,653 130.54 0.6173
2024-10-21 2024-09-30 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 1,559 -1,691 -52.03 718 -45.76 0.3274
2024-07-17 2024-06-30 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 3,250 1,712 111.31 1,322 104.64 0.5165
2024-04-15 2024-03-31 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 1,538 -51 -3.21 647 14.13 0.3119
2024-01-24 2023-12-31 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 1,589 16 1.02 567 2.72 0.2841
2023-10-17 2023-09-30 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 1,573 -436 -21.70 551 -19.56 0.3131
2023-07-21 2023-06-30 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 2,009 -1,729 -46.25 685 -40.64 0.3417
2023-04-24 2023-03-31 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 3,738 1,200 47.28 1,154 0.5459
2023-01-12 2022-12-31 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 2,538 94 3.85 1 -100.00 0.4427
2022-10-18 2022-09-30 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 2,444 2 0.08 653 -2.10 0.4108
2022-07-25 2022-06-30 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 2,442 65 2.73 667 -20.50 0.4506
2022-05-02 2022-03-31 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 2,377 596 33.46 839 57.41 0.7798
2022-02-07 2021-12-31 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 1,781 244 15.88 533 26.90 0.3470
2021-11-02 2021-09-30 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 1,537 66 4.49 420 2.69 0.3114
2021-08-02 2021-06-30 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 1,471 2 0.14 409 9.07 0.2682
2021-05-10 2021-03-31 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 1,469 152 11.54 375 22.95 0.2931
2021-02-03 2020-12-31 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 1,317 33 2.57 305 11.72 0.2541
2020-11-12 2020-09-30 13F/A-1 BERKSHIRE HATHAWAY CLASS B CS 084670702 1,284 104 8.81 273 29.38 0.2645
2020-08-07 2020-06-30 13F/A-1 BERKSHIRE HATHAWAY CLASS B CS 084670702 1,180 -22 -1.83 211 -4.09 0.2530
2020-05-07 2020-03-31 13F/A-1 BERKSHIRE HATHAWAY CLASS B CS 084670702 1,202 -74 -5.80 220 -23.88 0.3128
2020-01-28 2019-12-31 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 1,276 37 2.99 289 12.02 0.3035
2019-11-01 2019-09-30 13F/A-1 BERKSHIRE HATHAWAY CLASS B CS 084670702 1,239 -6 -0.48 258 -2.64 0.2988
2019-08-02 2019-06-30 13F BERKSHIRE HATHAWAY CLASS B CS 084670702 1,245 151 13.80 265 20.45 0.3045
2019-05-08 2019-03-31 13F BERKSHIRE HATHAWAY INC DEL CL CS 084670702 1,094 -1,775 -61.87 220 -62.46 0.2517
2019-02-19 2018-12-31 13F BERKSHIRE HATHAWAY INC DEL CL CS 084670702 2,869 2,869 586 0.5380
2018-08-07 2018-06-30 13F BERKSHIRE HATHAWAY INC DEL CL CS 084670702 0 -1,006 -100.00 0 -100.00
2018-05-08 2018-03-31 13F BERKSHIRE HATHAWAY INC DEL CL CS 084670702 1,006 1,006 201 0.2174
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.