Costco Wholesale Corporation
MX ˙ BMV ˙ US22160K1051
SecurityMX:COST / Costco Wholesale Corporation
InstitutionSomerset Trust Co
Latest Disclosed Ownership5,556 shares
Latest Disclosed Value $ 5,536,165
Somerset Trust Co reports 0.47% decrease in ownership of COST / Costco Wholesale Corporation

On April 2, 2026 - Somerset Trust Co filed a 13F-HR form disclosing ownership of 5,556 shares of Costco Wholesale Corporation (MX:COST) valued at $5,536,165 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 9, 2026 disclosing 5,582 shares of Costco Wholesale Corporation. This represents a change in shares of -0.47% 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)
2026-04-02 2026-03-31 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 5,556 -26 -0.47 5,536 15.02 1.6979
2026-01-09 2025-12-31 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 5,582 -181 -3.14 4,814 -9.77 1.4726
2025-10-14 2025-09-30 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 5,763 -4 -0.07 5,334 -6.55 1.6469
2025-07-07 2025-06-30 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 5,767 -150 -2.54 5,709 2.00 1.8606
2025-04-08 2025-03-31 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 5,917 -46 -0.77 5,596 2.43 1.9929
2025-01-15 2024-12-31 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 5,963 -293 -4.68 5,464 -1.50 2.0562
2024-10-08 2024-09-30 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 6,256 -105 -1.65 5,546 2.59 2.0749
2024-07-09 2024-06-30 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 6,361 -136 -2.09 5,407 13.60 2.2172
2024-04-05 2024-03-31 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 6,497 -577 -8.16 4,760 1.93 1.9418
2024-01-08 2023-12-31 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 7,074 -743 -9.50 4,669 5.73 2.0468
2023-10-17 2023-09-30 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 7,817 -209 -2.60 4,416 2.20 2.0137
2023-07-07 2023-06-30 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 8,026 -237 -2.87 4,321 5.26 1.8587
2023-04-05 2023-03-31 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 8,263 -78 -0.94 4,106 136,733.33 1.7800
2023-01-03 2022-12-31 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 8,341 57 0.69 4 -99.92 1.5971
2022-10-03 2022-09-30 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 8,284 -141 -1.67 3,912 -3.12 1.8217
2022-07-06 2022-06-30 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 8,425 -330 -3.77 4,038 -19.91 1.7691
2022-04-05 2022-03-31 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 8,755 -182 -2.04 5,042 -0.63 1.9504
2022-01-07 2021-12-31 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 8,937 -116 -1.28 5,074 24.73 1.8500
2021-10-07 2021-09-30 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 9,053 -329 -3.51 4,068 9.59 1.6614
2021-07-06 2021-06-30 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 9,382 6 0.06 3,712 12.31 1.5154
2021-04-07 2021-03-31 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 9,376 -91 -0.96 3,305 -7.35 1.4240
2021-01-25 2020-12-31 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 9,467 -96 -1.00 3,567 26.89 1.6228
2020-10-15 2020-09-30 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 9,563 -18 -0.19 2,811 -0.18 1.4153
2020-07-17 2020-06-30 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 9,581 -170 -1.74 2,816 -1.74 1.5012
2020-04-20 2020-03-31 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 9,751 -1,742 -15.16 2,866 -15.16 1.8799
2020-01-17 2019-12-31 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 11,493 -251 -2.14 3,378 -0.18 1.6697
2019-10-25 2019-09-30 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 11,744 -1,182 -9.14 3,384 -0.94 1.7870
2019-07-31 2019-06-30 13F COSTCO WHSL CORP NEW COM Common Stock 22160K105 12,926 -176 -1.34 3,416 7.69 1.7612
2019-04-09 2019-03-31 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 13,102 114 0.88 3,172 19.88 1.6684
2019-01-22 2018-12-31 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 12,988 -138 -1.05 2,646 -14.17 1.5381
2018-10-15 2018-09-30 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 13,126 -37 -0.28 3,083 12.07 1.5234
2018-07-19 2018-06-30 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 13,163 -1,007 -7.11 2,751 3.03 1.4771
2018-04-13 2018-03-31 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 14,170 -143 -1.00 2,670 0.23 1.3793
2018-01-17 2017-12-31 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 14,313 -636 -4.25 2,664 8.47 1.3308
2017-10-13 2017-09-30 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 14,949 1,261 9.21 2,456 12.20 1.3022
2017-07-13 2017-06-30 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 13,688 -207 -1.49 2,189 -6.05 1.1931
2017-04-18 2017-03-31 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 13,895 -249 -1.76 2,330 2.87 1.3074
2017-02-01 2016-12-31 13F/A-1 COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 14,144 -697 -4.70 2,265 0.09 1.3427
2017-01-25 2016-12-31 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 14,144 2,265
2016-10-18 2016-09-30 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 14,841 -159 -1.06 2,263 -3.95 1.3475
2016-07-13 2016-06-30 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 15,000 2,788 22.83 2,356 22.45 1.4552
2016-04-13 2016-03-31 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 12,212 -62 -0.51 1,924 -2.93 1.2763
2016-01-25 2015-12-31 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 12,274 -2,969 -19.48 1,982 -10.07 1.3030
2015-10-20 2015-09-30 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 15,243 109 0.72 2,204 7.83 1.5483
2015-07-14 2015-06-30 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 15,134 -22 -0.15 2,044 -10.98 1.3410
2015-04-16 2015-03-31 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 15,156 -4,897 -24.42 2,296 -19.21 1.5158
2015-01-09 2014-12-31 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 20,053 3,248 19.33 2,842 34.95 1.8914
2014-10-07 2014-09-30 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 16,805 -239 -1.40 2,106 7.28 1.4708
2014-07-09 2014-06-30 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 17,044 -302 -1.74 1,963 1.34 1.3909
2014-04-09 2014-03-31 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 17,346 -474 -2.66 1,937 -8.68 1.4755
2014-01-22 2013-12-31 13F COSTCO WHSL CORP NEW COM COMMON STOCK 22160K105 17,820 17,820 2,121 1.6125
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.