Costco Wholesale Corporation
MX ˙ BMV ˙ US22160K1051
SecurityMX:COST / Costco Wholesale Corporation
InstitutionKeystone Wealth Services, LLC
Latest Disclosed Ownership7,759 shares
Latest Disclosed Value $ 7,731,788
Keystone Wealth Services, LLC reports 11.05% decrease in ownership of COST / Costco Wholesale Corporation

On May 13, 2026 - Keystone Wealth Services, LLC filed a 13F-HR form disclosing ownership of 7,759 shares of Costco Wholesale Corporation (MX:COST) valued at $7,731,788 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 26, 2026 disclosing 8,723 shares of Costco Wholesale Corporation. This represents a change in shares of -11.05% 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)
2026-05-13 2026-03-31 13F COSTCO WHOLESALE COM 22160K105 7,759 -964 -11.05 7,732 2.78 1.6532
2026-01-26 2025-12-31 13F COSTCO WHSL CORP COM 22160K105 8,723 -34 -0.39 7,522 -7.19 1.5850
2025-10-22 2025-09-30 13F COSTCO WHSL CORP COM 22160K105 8,757 74 0.85 8,106 -5.70 1.7684
2025-07-09 2025-06-30 13F COSTCO WHSL CORP COM 22160K105 8,683 -925 -9.63 8,596 -5.40 2.0731
2025-04-17 2025-03-31 13F COSTCO WHSL CORP COM 22160K105 9,608 -442 -4.40 9,087 -1.32 2.4602
2025-02-06 2024-12-31 13F COSTCO WHSL CORP COM 22160K105 10,050 970 10.68 9,208 14.40 2.4380
2024-10-15 2024-09-30 13F COSTCO WHSL CORP COM 22160K105 9,080 5,028 124.09 8,049 133.71 2.2264
2024-07-12 2024-06-30 13F COSTCO WHSL CORP COM 22160K105 4,052 -17 -0.42 3,444 15.57 1.0717
2024-04-12 2024-03-31 13F COSTCO WHSL CORP COM 22160K105 4,069 -8 -0.20 2,981 10.74 0.9688
2024-01-17 2023-12-31 13F COSTCO WHSL CORP COM 22160K105 4,077 33 0.82 2,691 17.82 0.9224
2023-10-05 2023-09-30 13F COSTCO WHSL CORP COM 22160K105 4,044 -106 -2.55 2,285 2.24 0.8677
2023-07-20 2023-06-30 13F COSTCO WHSL CORP COM 22160K105 4,150 62 1.52 2,234 10.00 0.8349
2023-04-07 2023-03-31 13F COSTCO WHSL CORP COM 22160K105 4,088 20 0.49 2,031 9.37 0.8309
2023-02-10 2022-12-31 13F COSTCO WHSL CORP COM 22160K105 4,068 191 4.93 1,857 1.42 0.8101
2022-11-01 2022-09-30 13F COSTCO WHSL CORP COM 22160K105 3,877 38 0.99 1,831 -0.49 0.8645
2022-07-13 2022-06-30 13F COSTCO WHSL CORP COM 22160K105 3,839 77 2.05 1,840 -15.09 0.8231
2022-04-21 2022-03-31 13F COSTCO WHSL CORP COM 22160K105 3,762 62 1.68 2,167 3.14 0.8593
2022-02-14 2021-12-31 13F COSTCO WHSL CORP COM 22160K105 3,700 3,700 2,101 0.8525
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.