Costco Wholesale Corporation
MX ˙ BMV ˙ US22160K1051
SecurityMX:COST / Costco Wholesale Corporation
InstitutionAdirondack Trust Co
Latest Disclosed Ownership1,451 shares
Latest Disclosed Value $ 1,445,777
Adirondack Trust Co reports 1.69% decrease in ownership of COST / Costco Wholesale Corporation

On April 3, 2026 - Adirondack Trust Co filed a 13F-HR form disclosing ownership of 1,451 shares of Costco Wholesale Corporation (MX:COST) valued at $1,445,777 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 8, 2026 disclosing 1,476 shares of Costco Wholesale Corporation. This represents a change in shares of -1.69% 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)
2026-04-03 2026-03-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,451 -25 -1.69 1,446 13.60 0.4858
2026-01-08 2025-12-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,476 -37 -2.45 1,273 -9.14 0.4187
2025-10-20 2025-09-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,513 1 0.07 1,400 -6.42 0.4697
2025-07-11 2025-06-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,512 -33 -2.14 1,497 2.40 0.5434
2025-04-03 2025-03-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,545 -15 -0.96 1,461 2.24 0.5710
2025-01-17 2024-12-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,560 -37 -2.32 1,429 0.99 0.5458
2024-10-08 2024-09-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,597 -18 -1.11 1,416 3.13 0.5453
2024-07-09 2024-06-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,615 -4 -0.25 1,373 15.68 0.5605
2024-04-09 2024-03-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,619 -15 -0.92 1,186 -2.39 0.4964
2024-03-29 2023-12-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,634 -13 -0.79 1,215 30.65 0.5252
2023-10-31 2023-09-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,647 -52 -3.06 930 -2.31 0.4644
2023-08-09 2023-06-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,699 12 0.71 953 13.60 0.4451
2023-04-28 2023-03-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,687 -38 -2.20 838 6.48 0.4245
2023-01-13 2022-12-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,725 3 0.17 787 -3.20 0.4073
2022-10-13 2022-09-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,722 36 2.14 813 0.62 0.4543
2022-07-06 2022-06-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,686 43 2.62 808 -14.59 0.4332
2022-04-05 2022-03-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,643 151 10.12 946 11.69 0.4477
2022-01-13 2021-12-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,492 2 0.13 847 15.71 0.4040
2021-11-16 2021-09-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,490 -17 -1.13 732 22.82 0.3482
2021-07-15 2021-06-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,507 0 0.00 596 12.24 0.3006
2021-04-16 2021-03-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,507 105 7.49 531 7.49 0.2827
2021-02-12 2020-12-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,402 5 0.36 494 -0.40 0.2970
2020-10-05 2020-09-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,397 0 0.00 496 9.01 0.3253
2020-08-19 2020-06-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,397 -40 -2.78 455 10.98 0.3010
2020-04-23 2020-03-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,437 30 2.13 410 -4.65 0.3347
2020-02-11 2019-12-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,407 -45 -3.10 430 2.87 0.2821
2019-10-09 2019-09-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,452 5 0.35 418 9.42 0.2935
2019-07-15 2019-06-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,447 5 0.35 382 7.91 0.2666
2019-05-13 2019-03-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,442 -93 -6.06 354 13.10 0.2429
2019-01-18 2018-12-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,535 8 0.52 313 -12.81 0.2424
2018-10-22 2018-09-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,527 -39 -2.49 359 9.79 0.2421
2018-07-26 2018-06-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,566 0 0.00 327 5.83 0.2307
2018-05-03 2018-03-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,566 -388 -19.86 309 -15.11 0.2200
2018-01-10 2017-12-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,954 0 0.00 364 13.40 0.2642
2017-10-12 2017-09-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 1,954 -75 -3.70 321 -0.93 0.2520
2017-08-02 2017-06-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 2,029 -45 -2.17 324 -6.90 0.2609
2017-04-12 2017-03-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 2,074 -320 -13.37 348 -9.14 0.2431
2017-01-17 2016-12-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 2,394 -1,765 -42.44 383 -39.59 0.2669
2016-10-21 2016-09-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 4,159 -105 -2.46 634 -5.23 0.4562
2016-07-13 2016-06-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 4,264 -70 -1.62 669 -2.05 0.4762
2016-04-12 2016-03-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 4,334 -35 -0.80 683 3.48 0.5067
2016-02-08 2015-12-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 4,369 85 1.98 660 6.62 0.5222
2015-10-19 2015-09-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 4,284 3,830 843.61 619 914.75 0.4988
2015-07-30 2015-06-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 454 10 2.25 61 -8.96 0.0455
2015-04-07 2015-03-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 444 444 67 0.0501
2015-01-27 2014-12-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 0 -339 -100.00 0 -100.00
2014-10-28 2014-09-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 339 75 28.41 42 40.00 0.0319
2014-07-23 2014-06-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 264 100 60.98 30 66.67 0.0229
2014-04-17 2014-03-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 164 0 0.00 18 -10.00 0.0144
2014-01-07 2013-12-31 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 164 0 0.00 20 5.26 0.0162
2013-10-04 2013-09-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 164 0 0.00 19 5.56 0.0167
2013-08-14 2013-06-30 13F COSTCO WHSL CORP CONSUMER STAPLES 22160K105 164 164 18 0.0164
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.