Costco Wholesale Corporation
US ˙ NasdaqGS ˙ US22160K1051

SecurityCOST / Costco Wholesale Corporation
InstitutionWiley Bros.-aintree Capital, Llc
Latest Disclosed Ownership117,478 shares
Latest Disclosed Value $ 116,609,296
Wiley Bros.-aintree Capital, Llc reports 3.96% increase in ownership of COST / Costco Wholesale Corporation

On May 15, 2026 - Wiley Bros.-aintree Capital, Llc filed a 13F-HR form disclosing ownership of 117,478 shares of Costco Wholesale Corporation (US:COST) valued at $117,058,604 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 113,002 shares of Costco Wholesale Corporation. This represents a change in shares of 3.96% during the quarter. The current value of the position is $112,993,865 USD.

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)
2026-05-15 2026-03-31 13F COSTCO WHOLESALE COM 22160K105 117,478 4,476 3.96 116,609 19.78 0.5764
2026-02-17 2025-12-31 13F COSTCO WHSL CORP COM 22160K105 113,002 13,686 13.78 97,353 5.89 0.5093
2025-11-14 2025-09-30 13F COSTCO WHSL CORP COM 22160K105 99,316 9,045 10.02 91,941 2.83 0.5888
2025-08-14 2025-06-30 13F COSTCO WHSL CORP COM 22160K105 90,271 20,146 28.73 89,412 37.06 0.6860
2025-05-15 2025-03-31 13F COSTCO WHSL CORP COM 22160K105 70,125 9,626 15.91 65,237 17.60 0.6931
2025-02-14 2024-12-31 13F COSTCO WHSL CORP COM 22160K105 60,499 26,408 77.46 55,472 83.24 0.6652
2024-11-14 2024-09-30 13F COSTCO WHSL CORP COM 22160K105 34,091 17,174 101.52 30,274 110.43 0.5841
2024-07-24 2024-06-30 13F COSTCO WHSL CORP COM 22160K105 16,917 13,114 344.83 14,386 414.52 0.6297
2024-04-11 2024-03-31 13F COSTCO WHSL CORP COM 22160K105 3,803 2,630 224.21 2,796 266.93 0.3853
2024-01-09 2023-12-31 13F COSTCO WHSL CORP COM 22160K105 1,173 398 51.35 762 74.37 0.1857
2023-10-06 2023-09-30 13F COSTCO WHSL CORP COM 22160K105 775 11 1.44 438 6.33 0.2044
2023-07-05 2023-06-30 13F COSTCO WHSL CORP COM 22160K105 764 0 0.00 411 8.44 0.1841
2023-04-06 2023-03-31 13F COSTCO WHSL CORP COM 22160K105 764 17 2.28 379 11.47 0.1824
2023-01-10 2022-12-31 13F COSTCO WHSL CORP COM 22160K105 747 -48 -6.04 341 -9.57 0.1692
2022-10-11 2022-09-30 13F COSTCO WHSL CORP COM 22160K105 795 348 77.85 376 75.70 0.2175
2022-07-06 2022-06-30 13F COSTCO WHSL CORP COM 22160K105 447 447 214 0.1236
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.