Costco Wholesale Corporation
MX ˙ BMV ˙ US22160K1051
SecurityMX:COST / Costco Wholesale Corporation
InstitutionWinch Advisory Services, LLC
Latest Disclosed Ownership3,600 shares
Latest Disclosed Value $ 3,587,396
Winch Advisory Services, LLC reports 1.24% increase in ownership of COST / Costco Wholesale Corporation

On April 30, 2026 - Winch Advisory Services, LLC filed a 13F-HR form disclosing ownership of 3,600 shares of Costco Wholesale Corporation (MX:COST) valued at $3,587,396 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 3, 2026 disclosing 3,556 shares of Costco Wholesale Corporation. This represents a change in shares of 1.24% 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)
2026-04-30 2026-03-31 13F COSTCO WHOLESALE COM 22160K105 3,600 44 1.24 3,587 16.99 0.8189
2026-02-03 2025-12-31 13F COSTCO WHOLESALE COM 22160K105 3,556 148 4.34 3,066 -2.79 0.6783
2025-11-12 2025-09-30 13F COSTCO WHOLESALE COM 22160K105 3,408 148 4.54 3,154 -2.26 0.7097
2025-08-07 2025-06-30 13F COSTCO WHOLESALE COM 22160K105 3,260 -11 -0.34 3,228 4.30 0.7881
2025-05-06 2025-03-31 13F COSTCO WHOLESALE COM 22160K105 3,271 36 1.11 3,094 4.42 0.8180
2025-01-14 2024-12-31 13F COSTCO WHOLESALE COM 22160K105 3,235 31 0.97 2,964 4.33 0.7709
2024-10-21 2024-09-30 13F COSTCO WHOLESALE COM 22160K105 3,204 171 5.64 2,841 10.21 0.7856
2024-07-31 2024-06-30 13F COSTCO WHOLESALE COM 22160K105 3,033 -32 -1.04 2,578 14.79 0.7372
2024-05-14 2024-03-31 13F COSTCO WHOLESALE COM 22160K105 3,065 87 2.92 2,246 14.25 0.6860
2024-01-18 2023-12-31 13F COSTCO WHOLESALE COM 22160K105 2,978 46 1.57 1,966 196,400.00 0.6519
2023-11-06 2023-09-30 13F COSTCO WHOLESALE COM 22160K105 2,932 7 0.24 2 0.00 0.6075
2023-08-08 2023-06-30 13F COSTCO WHOLESALE COM 22160K105 2,925 57 1.99 2 0.00 0.5656
2023-05-10 2023-03-31 13F COSTCO WHOLESALE COM 22160K105 2,868 18 0.63 1 0.00 0.5529
2023-01-26 2022-12-31 13F COSTCO WHOLESALE COM 22160K105 2,850 -63 -2.16 1 -99.93 0.5550
2022-10-31 2022-09-30 13F COSTCO WHOLESALE COM 22160K105 2,913 14 0.48 1,376 -0.94 0.5910
2022-08-12 2022-06-30 13F COSTCO WHOLESALE COM 22160K105 2,899 -209 -6.72 1,389 -22.40 0.5668
2022-04-26 2022-03-31 13F COSTCO WHOLESALE CORP COM COM 22160K105 3,108 -148 -4.55 1,790 -3.19 0.6224
2022-02-04 2021-12-31 13F COSTCO WHOLESALE CORP COM COM 22160K105 3,256 -123 -3.64 1,849 21.81 0.6114
2021-11-10 2021-09-30 13F COSTCO WHOLESALE CORP COM COM 22160K105 3,379 14 0.42 1,518 14.05 0.5291
2021-08-05 2021-06-30 13F COSTCO WHOLESALE CORP COM COM 22160K105 3,365 126 3.89 1,331 16.55 0.4787
2021-05-03 2021-03-31 13F COSTCO WHOLESALE CORP COM COM 22160K105 3,239 467 16.85 1,142 9.39 0.4577
2021-02-09 2020-12-31 13F COSTCO WHOLESALE CORP COM COM 22160K105 2,772 426 18.16 1,044 25.33 0.4338
2020-11-04 2020-09-30 13F COSTCO WHOLESALE CORP COM COM 22160K105 2,346 4 0.17 833 17.32 0.3527
2020-08-12 2020-06-30 13F COSTCO WHOLESALE CORP COM COM 22160K105 2,342 72 3.17 710 9.74 0.3375
2020-05-13 2020-03-31 13F COSTCO WHOLESALE CORP COM COM 22160K105 2,270 103 4.75 647 1.57 0.3217
2020-02-12 2019-12-31 13F COSTCO WHOLESALE CORP COM COM 22160K105 2,167 1,124 107.77 637 111.63 0.3022
2019-11-13 2019-09-30 13F COSTCO WHOLESALE CORP COM COM 22160K105 1,043 1,025 5,694.44 301 5,920.00 0.1567
2019-08-07 2019-06-30 13F COSTCO WHOLESALE CORP COM COM 22160K105 18 9 100.00 5 150.00 0.0026
2019-05-13 2019-03-31 13F COSTCO WHOLESALE CORP COM COM 22160K105 9 4 80.00 2 100.00 0.0011
2019-02-05 2018-12-31 13F COSTCO WHOLESALE CORPORATION COM COM 22160K105 5 5 1 0.0006
2016-11-02 2016-09-30 13F COSTCO WHOLESALE CORPORATION COM COM 22160K105 0 -67 -100.00 0 -100.00
2016-08-10 2016-06-30 13F COSTCO WHOLESALE CORPORATION COM COM 22160K105 67 -25 -27.17 11 -26.67 0.0133
2016-05-12 2016-03-31 13F COSTCO WHOLESALE CORPORATION COM COM 22160K105 92 67 268.00 15 275.00 0.0242
2016-01-22 2015-12-31 13F COSTCO WHOLESALE CORPORATION COM COM 22160K105 25 25 0.00 4 0.0045
2015-08-11 2015-06-30 13F Costco Wholesale COM 22160K105 0 -12,684 -100.00 0 -100.00
2015-05-14 2015-03-31 13F Costco Wholesale COM 22160K105 12,684 -1,416 -10.04 1,922 -3.85 1.1195
2015-02-11 2014-12-31 13F COSTCO WHOLESALE CORPORATION COM COM 22160K105 14,100 9,290 193.14 1,999 231.51 1.0884
2014-11-14 2014-09-30 13F Costco Wholesale COM 22160K105 4,810 4,810 603 0.3867
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.