Costco Wholesale Corporation
MX ˙ BMV ˙ US22160K1051
SecurityMX:COST / Costco Wholesale Corporation
InstitutionWestern Wealth Management, LLC
Latest Disclosed Ownership19,195 shares
Latest Disclosed Value $ 19,126,139
Western Wealth Management, LLC reports 21.01% increase in ownership of COST / Costco Wholesale Corporation

On May 19, 2026 - Western Wealth Management, LLC filed a 13F-HR form disclosing ownership of 19,195 shares of Costco Wholesale Corporation (MX:COST) valued at $19,126,139 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 5, 2026 disclosing 15,862 shares of Costco Wholesale Corporation. This represents a change in shares of 21.01% 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.

Upgrade to unlock premium data and export to Excel .

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)
2026-05-19 2026-03-31 13F COSTCO WHOLESALE COM 22160K105 19,195 3,333 21.01 19,126 39.83 0.4445
2026-02-05 2025-12-31 13F COSTCO WHOLESALE Common Stock 22160K105 15,862 383 2.47 13,678 -4.54 0.6301
2025-11-06 2025-09-30 13F COSTCO WHOLESALE Common Stock 22160K105 15,479 391 2.59 14,328 -4.07 0.7557
2025-08-11 2025-06-30 13F COSTCO WHOLESALE Common Stock 22160K105 15,088 113 0.75 14,937 5.46 0.8863
2025-04-23 2025-03-31 13F COSTCO WHOLESALE Common Stock 22160K105 14,975 291 1.98 14,164 5.27 0.9373
2025-04-16 2024-12-31 13F/A-1 COSTCO WHOLESALE Common Stock 22160K105 14,684 -2,776 -15.90 13,455 -13.08 0.8766
2025-02-18 2024-12-31 13F COSTCO WHSL CORP COM 22160K105 2,689 -14,771 2,464 0.7399
2024-11-12 2024-09-30 13F COSTCO WHSL CORP COM 22160K105 17,460 2,426 16.14 15,478 21.13 0.8824
2024-07-19 2024-06-30 13F COSTCO WHSL CORP COM 22160K105 15,034 633 4.40 12,779 21.12 0.9471
2024-05-03 2024-03-31 13F COSTCO WHSL CORP COM 22160K105 14,401 -2,959 -17.04 10,551 -7.92 0.8201
2024-01-31 2023-12-31 13F COSTCO WHSL CORP COM 22160K105 17,360 246 1.44 11,459 18.51 0.8259
2023-11-08 2023-09-30 13F COSTCO WHSL CORP COM 22160K105 17,114 669 4.07 9,668 9.21 0.8169
2023-08-30 2023-06-30 13F COSTCO WHSL CORP COM 22160K105 16,445 422 2.63 8,854 11.20 0.7552
2023-08-30 2023-03-31 13F COSTCO WHSL CORP COM 22160K105 16,023 425 2.72 7,961 11.81 0.7409
2023-02-03 2022-12-31 13F COSTCO WHSL CORP COM 22160K105 15,598 -11,233 -41.87 7,121 -44.27 0.7278
2022-11-07 2022-09-30 13F COSTCO WHSL CORP COM 22160K105 26,831 2,961 12.40 12,775 10.98 0.7316
2022-07-18 2022-06-30 13F COSTCO WHSL CORP COM 22160K105 23,870 520 2.23 11,511 -14.38 0.6608
2022-05-10 2022-03-31 13F COSTCO WHSL CORP COM 22160K105 23,350 13,216 130.41 13,445 133.70 0.6524
2022-02-14 2021-12-31 13F COSTCO WHSL CORP COM 22160K105 10,134 -1,592 -13.58 5,753 23.64 0.5679
2021-08-09 2021-06-30 13F COSTCO WHSL CORP COM 22160K105 11,726 2,015 20.75 4,653 35.93 0.4784
2021-05-14 2021-03-31 13F COSTCO WHSL CORP COM 22160K105 9,711 -456 -4.49 3,423 -10.65 0.4601
2021-02-10 2020-12-31 13F COSTCO WHSL CORP COM 22160K105 10,167 68 0.67 3,831 6.80 0.5622
2020-10-27 2020-09-30 13F COSTCO WHSL CORP COM 22160K105 10,099 154 1.55 3,587 18.74 0.5859
2020-07-20 2020-06-30 13F COSTCO WHSL CORP COM 22160K105 9,945 594 6.35 3,021 13.23 0.5478
2020-04-27 2020-03-31 13F COSTCO WHSL CORP COM 22160K105 9,351 3,435 58.06 2,668 53.42 0.6119
2020-02-10 2019-12-31 13F COSTCO WHSL CORP COM 22160K105 5,916 241 4.25 1,739 6.75 0.2635
2019-11-08 2019-09-30 13F COSTCO WHSL CORP COM 22160K105 5,675 218 3.99 1,629 12.97 0.3390
2019-08-06 2019-06-30 13F COSTCO WHSL CORP COM 22160K105 5,457 -32 -0.58 1,442 8.58 0.1894
2019-05-10 2019-03-31 13F COSTCO WHSL CORP COM 22160K105 5,489 100 1.86 1,328 21.39 0.2956
2019-02-15 2018-12-31 13F COSTCO WHSL CORP COM 22160K105 5,389 5,389 1,094 0.2943
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.