Costco Wholesale Corporation
US ˙ NasdaqGS ˙ US22160K1051

SecurityCOST / Costco Wholesale Corporation
InstitutionCastleview Partners, Llc
Latest Disclosed Ownership259 shares
Latest Disclosed Value $ 258,075
Castleview Partners, Llc reports 3.19% increase in ownership of COST / Costco Wholesale Corporation

On May 1, 2026 - Castleview Partners, Llc filed a 13F-HR form disclosing ownership of 259 shares of Costco Wholesale Corporation (US:COST) valued at $258,075 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 12, 2026 disclosing 251 shares of Costco Wholesale Corporation. This represents a change in shares of 3.19% during the quarter. The current value of the position is $249,114 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)
2026-05-01 2026-03-31 13F COSTCO WHOLESALE COM 22160K105 259 8 3.19 258 19.44 0.1323
2026-01-12 2025-12-31 13F COSTCO WHSL CORP COM 22160K105 251 251 216 0.1073
2025-04-22 2025-03-31 13F COSTCO WHSL CORP COM 22160K105 0 -478 -100.00 0 -100.00
2025-01-21 2024-12-31 13F/A-1 COSTCO WHSL CORP COM 22160K105 478 -67 -12.29 435 -9.96 0.2341
2025-01-21 2024-12-31 13F COSTCO WHSL CORP COM 22160K105 545 0 483 0.2784
2024-10-21 2024-09-30 13F/A-1 COSTCO WHSL CORP COM 22160K105 545 25 4.81 483 9.30 0.2785
2024-10-09 2024-09-30 13F COSTCO WHSL CORP COM 22160K105 520 0 442 0.2512
2024-07-31 2024-06-30 13F COSTCO WHSL CORP COM 22160K105 520 -61 -10.50 442 3.76 0.2512
2024-05-10 2024-03-31 13F COSTCO WHSL CORP COM 22160K105 581 31 5.64 425 17.08 0.2376
2024-02-05 2023-12-31 13F COSTCO WHSL CORP COM 22160K105 550 450 450.00 363 548.21 0.2543
2023-10-26 2023-09-30 13F COSTCO WHSL CORP COM 22160K105 100 0 0.00 56 5.66 0.0522
2023-08-15 2023-06-30 13F COSTCO WHSL CORP COM 22160K105 100 -35 -25.93 54 -20.90 0.0485
2023-05-16 2023-03-31 13F COSTCO WHSL CORP COM 22160K105 135 0 0.00 67 9.84 0.0594
2023-02-01 2022-12-31 13F COSTCO WHSL CORP COM 22160K105 135 0 0.00 62 -4.69 0.0600
2022-11-10 2022-09-30 13F COSTCO WHSL CORP COM 22160K105 135 55 68.75 64 1,500.00 0.0611
2022-08-17 2022-06-30 13F/A-1 COSTAR GROUP Common 22160K105 80 -95 -54.29 5 -96.00 0.0038
2022-08-16 2022-06-30 13F COST Equity 22160K105 79,081 78,906 165 0.0019
2022-05-16 2022-03-31 13F COSTCO WHOLESALE Equity 22160K105 175 -139,195 -99.87 100 -59.18 0.0622
2022-02-17 2021-12-31 13F COST Equity 22160K105 139,370 139,045 42,783.08 245 89.92 0.0020
2021-08-17 2021-06-30 13F COST Equity 22160K105 325 325 129 0.0565
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.