Costco Wholesale Corporation
MX ˙ BMV ˙ US22160K1051
SecurityMX:COST / Costco Wholesale Corporation
InstitutionTufton Capital Management
Latest Disclosed Ownership2,250 shares
Latest Disclosed Value $ 2,241
Tufton Capital Management reports 10.18% decrease in ownership of COST / Costco Wholesale Corporation

On May 12, 2026 - Tufton Capital Management filed a 13F-HR form disclosing ownership of 2,250 shares of Costco Wholesale Corporation (MX:COST) valued at $2,241 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 28, 2026 disclosing 2,505 shares of Costco Wholesale Corporation. This represents a change in shares of -10.18% 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 COSTCO WHOLESALE CORPORATION C COM 22160K105 2,250 -255 -10.18 2 0.00 0.4077
2026-01-28 2025-12-31 13F COSTCO WHOLESALE COM 22160K105 2,505 -162 -6.07 2 0.00 0.3776
2025-10-31 2025-09-30 13F COSTCO WHOLESALE COM 22160K105 2,667 9 0.34 2 0.00 0.4399
2025-08-05 2025-06-30 13F COSTCO WHOLESALE COM 22160K105 2,658 -5 -0.19 3 -99.92 0.5002
2025-05-06 2025-03-31 13F COSTCO WHOLESALE COM 22160K105 2,663 59 2.27 2,519 5.58 0.4851
2025-02-05 2024-12-31 13F COSTCO WHOLESALE COM 22160K105 2,604 27 1.05 2,386 4.42 0.4513
2024-11-08 2024-09-30 13F COSTCO WHOLESALE COM 22160K105 2,577 35 1.38 2,285 5.74 0.4283
2024-07-31 2024-06-30 13F COSTCO WHOLESALE COM 22160K105 2,542 -17 -0.66 2,161 15.26 0.4202
2024-05-07 2024-03-31 13F COSTCO WHOLESALE COM 22160K105 2,559 -27 -1.04 1,875 9.85 0.3682
2024-01-31 2023-12-31 13F COSTCO WHOLESALE CRP DEL COM 22160K105 2,586 -295 -10.24 1,707 4.86 0.3581
2023-10-30 2023-09-30 13F/A-1 COSTCO WHOLESALE CRP DEL COM 22160K105 2,881 82 2.93 1,628 8.03 0.3631
2023-10-30 2023-09-30 13F COSTCO WHOLESALE CRP DEL COM 22160K105 2,881 82 1,628 0.3631
2023-07-28 2023-06-30 13F COSTCO WHOLESALE CRP DEL COM 22160K105 2,799 -401 -12.53 1,507 -5.22 0.3251
2023-04-19 2023-03-31 13F COSTCO WHOLESALE CRP DEL COM 22160K105 3,200 7 0.22 1,590 9.06 0.3439
2023-01-26 2022-12-31 13F COSTCO WHOLESALE CRP DEL COM 22160K105 3,193 177 5.87 1,458 2.32 0.3207
2022-10-21 2022-09-30 13F COSTCO WHOLESALE CRP DEL COM 22160K105 3,016 5 0.17 1,424 -1.32 0.3437
2022-07-20 2022-06-30 13F COSTCO WHOLESALE CRP DEL COM 22160K105 3,011 -20 -0.66 1,443 -17.31 0.2696
2022-04-25 2022-03-31 13F COSTCO WHOLESALE CRP DEL COM 22160K105 3,031 -70 -2.26 1,745 -0.85 0.2821
2022-01-28 2021-12-31 13F COSTCO WHOLESALE CRP DEL COM 22160K105 3,101 15 0.49 1,760 26.98 0.2702
2021-10-21 2021-09-30 13F COSTCO WHOLESALE CRP DEL COM 22160K105 3,086 5 0.16 1,386 13.70 0.2346
2021-07-29 2021-06-30 13F COSTCO WHOLESALE CRP DEL COM 22160K105 3,081 0 0.00 1,219 12.35 0.2002
2021-04-22 2021-03-31 13F COSTCO WHOLESALE CRP DEL COM 22160K105 3,081 150 5.12 1,085 -1.72 0.1854
2021-02-01 2020-12-31 13F COSTCO WHOLESALE CRP DEL COM 22160K105 2,931 -327 -10.04 1,104 -4.50 0.2036
2020-10-23 2020-09-30 13F COSTCO WHOLESALE CRP DEL COM 22160K105 3,258 950 41.16 1,156 65.38 0.2388
2020-07-27 2020-06-30 13F COSTCO WHOLESALE CRP DEL COM 22160K105 2,308 33 1.45 699 7.87 0.1539
2020-04-23 2020-03-31 13F COSTCO WHOLESALE CRP DEL COM 22160K105 2,275 -100 -4.21 648 -7.16 0.1661
2020-01-24 2019-12-31 13F COSTCO WHOLESALE CRP DEL COM 22160K105 2,375 0 0.00 698 2.05 0.1374
2019-10-25 2019-09-30 13F COSTCO WHOLESALE CRP DEL COM 22160K105 2,375 0 0.00 684 9.09 0.1443
2019-07-26 2019-06-30 13F COSTCO WHSL CORP NEW COM COM 22160K105 2,375 0 0.00 627 9.04 0.1326
2019-04-29 2019-03-31 13F COSTCO WHSL CORP NEW COM COM 22160K105 2,375 50 2.15 575 21.56 0.1225
2019-01-28 2018-12-31 13F COSTCO WHSL CORP NEW COM COM 22160K105 2,325 -100 -4.12 473 -16.87 0.1160
2018-10-26 2018-09-30 13F COSTCO WHSL CORP NEW COM COM 22160K105 2,425 0 0.00 569 12.45 0.1210
2018-08-06 2018-06-30 13F COSTCO WHSL CORP NEW COM COM 22160K105 2,425 -500 -17.09 506 -8.17 0.1085
2018-04-23 2018-03-31 13F COSTCO WHSL CORP NEW COM COM 22160K105 2,925 0 0.00 551 1.29 0.1087
2018-01-26 2017-12-31 13F COSTCO WHSL CORP NEW COM COM 22160K105 2,925 0 0.00 544 13.10 0.1048
2017-10-20 2017-09-30 13F COSTCO WHSL CORP NEW COM COM 22160K105 2,925 -30 -1.02 481 1.69 0.0962
2017-07-28 2017-06-30 13F COSTCO WHSL CORP NEW COM COM 22160K105 2,955 30 1.03 473 -3.47 0.0960
2017-04-28 2017-03-31 13F COSTCO WHSL CORP NEW COM COM 22160K105 2,925 2,925 490 0.0966
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.