Costco Wholesale Corporation
US ˙ NasdaqGS ˙ US22160K1051

SecurityCOST / Costco Wholesale Corporation
InstitutionTarbox Family Office, Inc.
Latest Disclosed Ownership721 shares
Latest Disclosed Value $ 718,426
Tarbox Family Office, Inc. reports 17.51% decrease in ownership of COST / Costco Wholesale Corporation

On April 23, 2026 - Tarbox Family Office, Inc. filed a 13F-HR form disclosing ownership of 721 shares of Costco Wholesale Corporation (US:COST) valued at $718,426 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 21, 2026 disclosing 874 shares of Costco Wholesale Corporation. This represents a change in shares of -17.51% during the quarter. The current value of the position is $693,479 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)
2026-04-23 2026-03-31 13F COSTCO WHOLESALE COM 22160K105 721 -153 -17.51 718 -4.65 0.1167
2026-01-21 2025-12-31 13F COSTCO WHSL CORP COM 22160K105 874 -19 -2.13 754 -8.84 0.1213
2025-10-24 2025-09-30 13F COSTCO WHSL CORP COM 22160K105 893 1 0.11 827 -6.46 0.1213
2025-08-12 2025-06-30 13F COSTCO WHSL CORP COM 22160K105 892 -2 -0.22 883 4.50 0.1328
2025-05-08 2025-03-31 13F COSTCO WHSL CORP COM 22160K105 894 -3 -0.33 846 2.92 0.1405
2025-01-17 2024-12-31 13F COSTCO WHSL CORP COM 22160K105 897 3 0.34 822 3.66 0.1356
2024-10-23 2024-09-30 13F COSTCO WHSL CORP COM 22160K105 894 149 20.00 793 25.12 0.1299
2024-07-17 2024-06-30 13F COSTCO WHSL CORP COM 22160K105 745 0 0.00 633 16.15 0.1117
2024-04-16 2024-03-31 13F COSTCO WHSL CORP COM 22160K105 745 0 0.00 546 11.00 0.0959
2024-02-08 2023-12-31 13F COSTCO WHSL CORP COM 22160K105 745 1 0.13 492 16.90 0.0956
2023-10-13 2023-09-30 13F COSTCO WHSL CORP COM 22160K105 744 1 0.13 420 5.00 0.0871
2023-07-20 2023-06-30 13F COSTCO WHSL CORP COM 22160K105 743 -2 -0.27 400 8.11 0.0778
2023-04-11 2023-03-31 13F COSTCO WHSL CORP COM 22160K105 745 -1 -0.13 370 8.82 0.0748
2023-01-25 2022-12-31 13F COSTCO WHSL CORP COM 22160K105 746 -4 -0.53 341 -5.29 0.0746
2022-10-14 2022-09-30 13F COSTCO WHSL CORP COM 22160K105 750 -500 -40.00 359 -40.07 0.0851
2022-07-19 2022-06-30 13F COSTCO WHSL CORP COM 22160K105 1,250 499 66.44 599 38.66 0.1345
2022-04-25 2022-03-31 13F COSTCO WHSL CORP COM 22160K105 751 -851 -53.12 432 -52.48 0.0877
2022-01-06 2021-12-31 13F COSTCO WHSL CORP COM 22160K105 1,602 -499 -23.75 909 -3.71 0.1565
2021-10-12 2021-09-30 13F COSTCO WHSL CORP COM 22160K105 2,101 -1,001 -32.27 944 -23.06 0.1728
2021-07-16 2021-06-30 13F COSTCO WHSL CORP COM 22160K105 3,102 1,567 102.08 1,227 126.80 0.2193
2021-04-27 2021-03-31 13F COSTCO WHSL CORP COM 22160K105 1,535 -27 -1.73 541 -8.15 0.1065
2021-01-27 2020-12-31 13F COSTCO WHSL CORP COM 22160K105 1,562 -2 -0.13 589 6.13 0.1231
2020-10-22 2020-09-30 13F COSTCO WHSL CORP COM 22160K105 1,564 -477 -23.37 555 -10.34 0.1351
2020-07-23 2020-06-30 13F COSTCO WHSL CORP COM 22160K105 2,041 41 2.05 619 8.60 0.1601
2020-04-30 2020-03-31 13F COSTCO WHSL CORP COM 22160K105 2,000 -439 -18.00 570 -20.50 0.1846
2020-01-31 2019-12-31 13F COSTCO WHSL CORP COM 22160K105 2,439 -5 -0.20 717 1.85 0.1958
2019-10-25 2019-09-30 13F COSTCO WHSL CORP COM 22160K105 2,444 0 0.00 704 8.98 0.2141
2019-08-02 2019-06-30 13F COSTCO WHSL CORP COM 22160K105 2,444 18 0.74 646 10.05 0.2021
2019-04-24 2019-03-31 13F COSTCO WHSL CORP COM 22160K105 2,426 0 0.00 587 18.83 0.2146
2019-02-01 2018-12-31 13F COSTCO WHSL CORP COM 22160K105 2,426 0 0.00 494 -13.33 0.2046
2018-10-26 2018-09-30 13F COSTCO WHSL CORP COM 22160K105 2,426 689 39.67 570 57.02 0.2062
2018-07-31 2018-06-30 13F COSTCO WHOLESALE Stock 22160K105 1,737 0 0.00 363 11.01 0.1399
2018-04-24 2018-03-31 13F COSTCO WHOLESALE Stock 22160K105 1,737 -4 -0.23 327 0.93 0.1263
2018-01-26 2017-12-31 13F COSTCO WHSL CORP NEW COM Stock 22160K105 1,741 26 1.52 324 14.89 0.1286
2017-10-19 2017-09-30 13F COSTCO WHSL CORP NEW COM Stock 22160K105 1,715 16 0.94 282 3.68 0.1236
2017-07-18 2017-06-30 13F COSTCO WHSL CORP NEW COM Stock 22160K105 1,699 400 30.79 272 24.77 0.1341
2017-04-28 2017-03-31 13F COSTCO WHSL CORP NEW COM Stock 22160K105 1,299 800 160.32 218 172.50 0.1126
2017-01-31 2016-12-31 13F COSTCO WHSL CORP NEW COM Stock 22160K105 499 344 221.94 80 233.33 0.0459
2016-10-28 2016-09-30 13F COSTCO WHSL CORP NEW COM Stock 22160K105 155 3 1.97 24 0.00 0.0155
2016-07-29 2016-06-30 13F COSTCO WHSL CORP NEW COM Stock 22160K105 152 0 0.00 24 0.00 0.0172
2016-04-27 2016-03-31 13F COSTCO WHOLESALE Stock 22160K105 152 3 2.01 24 0.00 0.0182
2016-01-29 2015-12-31 13F COSTCO WHSL CORP NEW COM Stock 22160K105 149 3 2.05 24 14.29 0.0195
2015-10-30 2015-09-30 13F COSTCO WHSL CORP NEW COM Stock 22160K105 146 3 2.10 21 10.53 0.0192
2015-07-16 2015-06-30 13F COSTCO WHOLESALE Stock 22160K105 143 0 0.00 19 -13.64 0.0165
2015-04-20 2015-03-31 13F COSTCO WHSL CORP NEW COM Stock 22160K105 143 0 0.00 22 10.00 0.0193
2015-01-21 2014-12-31 13F COSTCO WHSL CORP NEW COM Stock 22160K105 143 0 0.00 20 11.11 0.0185
2014-10-14 2014-09-30 13F COSTCO WHSL CORP NEW COM COM 22160K105 143 12 9.16 18 20.00 0.0162
2014-07-11 2014-06-30 13F COSTCO WHOLESALE COM 22160K105 131 0 0.00 15 7.14 0.0134
2014-05-01 2014-03-31 13F COSTCO WHOLESALE COM 22160K105 131 -1,200 -90.16 14 -91.14 0.0125
2014-02-14 2013-12-31 13F COSTCO WHOLESALE CORP Total COM 22160K105 1,331 1,331 158 0.1318
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.