Costco Wholesale Corporation
US ˙ NasdaqGS ˙ US22160K1051

SecurityCOST / Costco Wholesale Corporation
InstitutionSigma Planning Corp
Latest Disclosed Ownership14,838 shares
Latest Disclosed Value $ 14,784,811
Sigma Planning Corp reports 6.72% decrease in ownership of COST / Costco Wholesale Corporation

On May 4, 2026 - Sigma Planning Corp filed a 13F-HR form disclosing ownership of 14,838 shares of Costco Wholesale Corporation (US:COST) valued at $14,785,028 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 30, 2026 disclosing 15,907 shares of Costco Wholesale Corporation. This represents a change in shares of -6.72% during the quarter. The current value of the position is $14,271,634 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)
2026-05-04 2026-03-31 13F COSTCO WHOLESALE COM 22160K105 14,838 -1,069 -6.72 14,785 7.78 0.4106
2026-01-30 2025-12-31 13F COSTCO WHSL CORP COM 22160K105 15,907 280 1.79 13,717 -5.16 0.3787
2025-11-10 2025-09-30 13F COSTCO WHSL CORP COM 22160K105 15,627 -61 -0.39 14,465 -6.86 0.4112
2025-08-05 2025-06-30 13F COSTCO WHSL CORP COM 22160K105 15,688 -3,754 -19.31 15,530 -15.54 0.4669
2025-05-02 2025-03-31 13F COSTCO WHSL CORP COM 22160K105 19,442 2,331 13.62 18,388 17.28 0.5864
2025-02-03 2024-12-31 13F COSTCO WHSL CORP COM 22160K105 17,111 -124 -0.72 15,679 2.61 0.4923
2024-11-04 2024-09-30 13F COSTCO WHSL CORP COM 22160K105 17,235 424 2.52 15,279 6.93 0.4680
2024-08-06 2024-06-30 13F COSTCO WHSL CORP COM 22160K105 16,811 -887 -5.01 14,289 10.20 0.4528
2024-05-02 2024-03-31 13F COSTCO WHSL CORP COM 22160K105 17,698 8,305 88.42 12,966 109.13 0.4075
2024-02-01 2023-12-31 13F COSTCO WHSL CORP COM 22160K105 9,393 -7,165 -43.27 6,200 -33.73 0.4851
2023-11-06 2023-09-30 13F COSTCO WHSL CORP COM 22160K105 16,558 233 1.43 9,355 6.44 0.3507
2023-08-02 2023-06-30 13F COSTCO WHSL CORP COM 22160K105 16,325 -1,927 -10.56 8,789 -3.09 0.3156
2023-05-08 2023-03-31 13F COSTCO WHSL CORP COM 22160K105 18,252 -1,154 -5.95 9,069 2.37 0.3014
2023-01-24 2022-12-31 13F COSTCO WHSL CORP COM 22160K105 19,406 -130 -0.67 8,859 -3.99 0.3167
2022-11-10 2022-09-30 13F COSTCO WHSL CORP COM 22160K105 19,536 1,251 6.84 9,227 5.28 0.3517
2022-08-11 2022-06-30 13F COSTCO WHSL CORP COM 22160K105 18,285 -1,126 -5.80 8,764 -21.60 0.3046
2022-04-20 2022-03-31 13F COSTCO WHSL CORP COM 22160K105 19,411 -1,576 -7.51 11,178 -6.19 0.3349
2022-02-02 2021-12-31 13F COSTCO WHOLESALE Stock 22160K105 20,987 1,796 9.36 11,915 38.16 0.3321
2021-10-28 2021-09-30 13F COSTCO WHSL CORP COM 22160K105 19,191 -1,091 -5.38 8,624 7.46 0.2594
2021-08-13 2021-06-30 13F COSTCO WHOLESALE Stock 22160K105 20,282 -2,642 -11.53 8,025 -0.68 0.2392
2021-05-06 2021-03-31 13F COSTCO WHOLESALE Stock 22160K105 22,924 1,143 5.25 8,080 -1.55 0.2581
2021-02-09 2020-12-31 13F COSTCO WHSL CORP COM 22160K105 21,781 1,182 5.74 8,207 12.22 0.2791
2020-11-03 2020-09-30 13F COSTCO WHSL CORP COM 22160K105 20,599 -132 -0.64 7,313 16.34 0.2894
2020-07-31 2020-06-30 13F COSTCO WHSL CORP COM 22160K105 20,731 5,342 34.71 6,286 43.25 0.2759
2020-05-01 2020-03-31 13F COSTCO WHSL CORP COM 22160K105 15,389 -115 -0.74 4,388 -3.71 0.2605
2020-02-03 2019-12-31 13F COSTCO WHSL CORP COM 22160K105 15,504 1,627 11.72 4,557 13.98 0.1922
2019-11-01 2019-09-30 13F COSTCO WHSL CORP COM 22160K105 13,877 1,220 9.64 3,998 19.52 0.1919
2019-08-01 2019-06-30 13F COSTCO WHSL CORP COM 22160K105 12,657 238 1.92 3,345 11.24 0.1723
2019-05-01 2019-03-31 13F COSTCO WHSL CORP COM 22160K105 12,419 1,047 9.21 3,007 29.78 0.1707
2019-01-31 2018-12-31 13F COSTCO WHSL CORP COM 22160K105 11,372 276 2.49 2,317 -11.09 0.1685
2018-11-07 2018-09-30 13F COSTCO WHSL CORP COM 22160K105 11,096 -327 -2.86 2,606 9.17 0.1532
2018-08-02 2018-06-30 13F COSTCO WHSL CORP COM 22160K105 11,423 -163 -1.41 2,387 9.34 0.1598
2018-05-11 2018-03-31 13F COSTCO WHSL CORP COM 22160K105 11,586 -54 -0.46 2,183 0.74 0.1596
2018-02-07 2017-12-31 13F COSTCO WHSL CORP COM 22160K105 11,640 -2,766 -19.20 2,167 -8.45 0.1669
2017-11-06 2017-09-30 13F COSTCO WHSL CORP COM 22160K105 14,406 3,203 28.59 2,367 32.09 0.1952
2017-08-02 2017-06-30 13F COSTCO WHSL CORP COM 22160K105 11,203 2,472 28.31 1,792 22.40 0.1684
2017-04-24 2017-03-31 13F COSTCO WHSL CORP COM 22160K105 8,731 -650 -6.93 1,464 -2.53 0.1418
2017-01-23 2016-12-31 13F COSTCO WHSL CORP COM 22160K105 9,381 -760 -7.49 1,502 -2.91 0.1642
2016-11-07 2016-09-30 13F COSTCO WHSL CORP COM 22160K105 10,141 1,551 18.06 1,547 14.68 0.1834
2016-07-22 2016-06-30 13F COSTCO WHSL CORP COM 22160K105 8,590 1,172 15.80 1,349 15.40 0.1759
2016-04-18 2016-03-31 13F COSTCO WHSL CORP COM 22160K105 7,418 -1,277 -14.69 1,169 -16.74 0.1598
2016-01-20 2015-12-31 13F COSTCO WHSL CORP COM 22160K105 8,695 2,466 39.59 1,404 55.83 0.1965
2015-11-02 2015-09-30 13F COSTCO WHSL CORP COM 22160K105 6,229 -330 -5.03 901 1.69 0.1427
2015-07-14 2015-06-30 13F COSTCO WHSL CORP COM 22160K105 6,559 -181 -2.69 886 -13.22 0.1223
2015-04-23 2015-03-31 13F COSTCO WHSL CORP COM 22160K105 6,740 770 12.90 1,021 20.69 0.1353
2015-02-13 2014-12-31 13F COSTCO WHSL CORP COM 22160K105 5,970 5,970 846 0.1118
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.