Costco Wholesale Corporation
MX ˙ BMV ˙ US22160K1051
SecurityMX:COST / Costco Wholesale Corporation
InstitutionBay Rivers Group
Latest Disclosed Ownership6,170 shares
Latest Disclosed Value $ 6,147,599
Bay Rivers Group reports 1.22% decrease in ownership of COST / Costco Wholesale Corporation

On April 13, 2026 - Bay Rivers Group filed a 13F-HR form disclosing ownership of 6,170 shares of Costco Wholesale Corporation (MX:COST) valued at $6,147,599 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 7, 2026 disclosing 6,246 shares of Costco Wholesale Corporation. This represents a change in shares of -1.22% 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)
2026-04-13 2026-03-31 13F COSTCO WHOLESALE COM 22160K105 6,170 -76 -1.22 6,148 14.15 2.5610
2026-01-07 2025-12-31 13F COSTCO WHSL CORP COM 22160K105 6,246 331 5.60 5,386 -1.63 2.1783
2025-10-08 2025-09-30 13F COSTCO WHSL CORP COM 22160K105 5,915 32 0.54 5,475 -5.99 2.3052
2025-07-09 2025-06-30 13F COSTCO WHSL CORP COM 22160K105 5,883 -4 -0.07 5,823 4.60 2.6638
2025-04-10 2025-03-31 13F COSTCO WHSL CORP COM 22160K105 5,887 90 1.55 5,567 4.82 2.9189
2025-01-22 2024-12-31 13F COSTCO WHSL CORP COM 22160K105 5,797 -42 -0.72 5,311 2.61 2.5744
2024-10-25 2024-09-30 13F COSTCO WHSL CORP COM 22160K105 5,839 50 0.86 5,176 5.20 2.5718
2024-07-22 2024-06-30 13F COSTCO WHSL CORP COM 22160K105 5,789 -38 -0.65 4,920 15.28 2.5577
2024-04-22 2024-03-31 13F COSTCO WHSL CORP COM 22160K105 5,827 167 2.95 4,269 14.27 2.3436
2024-01-12 2023-12-31 13F COSTCO WHSL CORP COM 22160K105 5,660 329 6.17 3,736 24.05 2.3451
2023-10-05 2023-09-30 13F COSTCO WHSL CORP COM 22160K105 5,331 83 1.58 3,012 6.58 2.3169
2023-07-13 2023-06-30 13F COSTCO WHSL CORP COM 22160K105 5,248 -118 -2.20 2,825 5.96 2.1177
2023-04-18 2023-03-31 13F COSTCO WHSL CORP COM 22160K105 5,366 17 0.32 2,666 9.22 2.3305
2023-01-17 2022-12-31 13F COSTCO WHSL CORP COM 22160K105 5,349 -57 -1.05 2,442 -4.39 2.4728
2022-10-12 2022-09-30 13F COSTCO WHSL CORP COM 22160K105 5,406 28 0.52 2,553 -0.93 2.5519
2022-07-12 2022-06-30 13F COSTCO WHSL CORP COM 22160K105 5,378 716 15.36 2,577 -3.99 2.2948
2022-04-20 2022-03-31 13F COSTCO WHSL CORP COM 22160K105 4,662 -97 -2.04 2,684 -0.63 1.9314
2022-01-20 2021-12-31 13F COSTCO WHSL CORP COM 22160K105 4,759 181 3.95 2,701 31.31 1.6509
2021-10-13 2021-09-30 13F COSTCO WHSL CORP COM 22160K105 4,578 -1,408 -23.52 2,057 -13.13 1.3985
2021-07-14 2021-06-30 13F COSTCO WHSL CORP COM 22160K105 5,986 -13 -0.22 2,368 11.96 1.6809
2021-04-14 2021-03-31 13F COSTCO WHSL CORP COM 22160K105 5,999 2,933 95.66 2,115 83.12 1.6439
2021-01-15 2020-12-31 13F COSTCO WHSL CORP COM 22160K105 3,066 52 1.73 1,155 7.94 0.9673
2020-10-08 2020-09-30 13F COSTCO WHSL CORP COM 22160K105 3,014 -464 -13.34 1,070 1.42 1.0068
2020-07-09 2020-06-30 13F COSTCO WHSL CORP COM 22160K105 3,478 3,478 1,055 1.0913
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.