Costco Wholesale Corporation
MX ˙ BMV ˙ US22160K1051
SecurityMX:COST / Costco Wholesale Corporation
InstitutionKlingenstein Fields & Co Lp
Latest Disclosed Ownership50,027 shares
Latest Disclosed Value $ 49,847,980
Klingenstein Fields & Co Lp ownership in COST / Costco Wholesale Corporation

On May 12, 2026 - Klingenstein Fields & Co Lp filed a 13F-HR form disclosing ownership of 50,027 shares of Costco Wholesale Corporation (MX:COST) valued at $49,847,980 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 50,467 shares of Costco Wholesale Corporation. This represents a change in shares of -0.87% during the quarter.

Klingenstein Fields & Co Lp has a history of taking positions in derivatives of the underlying security (COST) in the form of stock options.

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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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

MX:COST / Costco Wholesale Corporation Historical Put/Call Ratio
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)
2026-05-12 2026-03-31 13F COSTCO WHSL COMMON 22160K105 50,027 -440 -0.87 49,848 14.54 1.4622
2026-02-13 2025-12-31 13F COSTCO WHSL COMMON 22160K105 50,467 -564 -1.11 43,519 -7.87 1.6324
2025-11-14 2025-09-30 13F COSTCO WHSL COMMON 22160K105 51,031 -155 -0.30 47,236 -6.78 1.7836
2025-07-30 2025-06-30 13F COSTCO WHSL CORP COM 22160K105 51,186 -2,994 -5.53 50,671 -1.11 2.0062
2025-04-28 2025-03-31 13F COSTCO WHSL CORP COM 22160K105 54,180 -307 -0.56 51,243 2.64 2.1787
2025-01-30 2024-12-31 13F COSTCO WHSL CORP COM 22160K105 54,487 -658 -1.19 49,925 2.12 2.0122
2024-10-29 2024-09-30 13F COSTCO WHSL CORP COM 22160K105 55,145 -1,598 -2.82 48,887 1.36 1.9434
2024-08-01 2024-06-30 13F COSTCO WHSL CORP COM 22160K105 56,743 -647 -1.13 48,231 14.71 1.9982
2024-04-29 2024-03-31 13F COSTCO WHSL CORP COM 22160K105 57,390 -1,856 -3.13 42,046 7.51 1.7461
2024-02-01 2023-12-31 13F COSTCO WHSL CORP COM 22160K105 59,246 -1,810 -2.96 39,107 13.37 1.7432
2023-10-27 2023-09-30 13F COSTCO WHSL CORP COM 22160K105 61,056 -625 -1.01 34,494 3.88 1.6843
2023-08-01 2023-06-30 13F COSTCO WHSL CORP COM 22160K105 61,681 -833 -1.33 33,208 6.91 1.5348
2023-04-28 2023-03-31 13F COSTCO WHSL CORP COM 22160K105 62,514 -471 -0.75 31,061 8.03 1.5549
2023-02-02 2022-12-31 13F COSTCO WHSL CORP COM 22160K105 62,985 -839 -1.31 28,753 -4.61 1.4926
2022-10-28 2022-09-30 13F COSTCO WHSL CORP COM 22160K105 63,824 -329 -0.51 30,142 -1.97 1.6576
2022-08-01 2022-06-30 13F COSTCO WHSL CORP COM 22160K105 64,153 -223 -0.35 30,747 -17.06 1.5989
2022-04-27 2022-03-31 13F COSTCO WHSL CORP COM 22160K105 64,376 -2,106 -3.17 37,071 -1.78 1.5878
2022-01-31 2021-12-31 13F COSTCO WHSL CORP COM 22160K105 66,482 -519 -0.77 37,741 25.36 1.5167
2021-10-26 2021-09-30 13F COSTCO WHSL CORP COM 22160K105 67,001 -283 -0.42 30,107 13.09 1.2841
2021-07-26 2021-06-30 13F COSTCO WHSL CORP COM 22160K105 67,284 482 0.72 26,622 13.06 1.1014
2021-04-29 2021-03-31 13F COSTCO WHSL CORP COM 22160K105 66,802 -902 -1.33 23,546 -7.70 1.0645
2021-02-02 2020-12-31 13F COSTCO WHSL CORP COM 22160K105 67,704 3,563 5.55 25,509 12.03 1.1564
2020-10-30 2020-09-30 13F COSTCO WHSL CORP COM 22160K105 64,141 7,174 12.59 22,770 31.82 1.1368
2020-08-03 2020-06-30 13F COSTCO WHSL CORP COM 22160K105 56,967 40,782 251.97 17,273 274.28 0.9437
2020-05-07 2020-03-31 13F COSTCO WHSL CORP COM 22160K105 16,185 -24 -0.15 4,615 -3.13 0.3007
2020-02-04 2019-12-31 13F COSTCO WHSL CORP COM 22160K105 16,209 -267 -1.62 4,764 0.36 0.2397
2019-11-01 2019-09-30 13F COSTCO WHSL CORP COM 22160K105 16,476 -860 -4.96 4,747 3.62 0.2506
2019-08-12 2019-06-30 13F COSTCO WHSL CORP COM 22160K105 17,336 -330 -1.87 4,581 7.08 0.2378
2019-04-29 2019-03-31 13F COSTCO WHSL CORP COM 22160K105 17,666 -135 -0.76 4,278 17.98 0.2299
2019-01-22 2018-12-31 13F Costco Wholesale COM 22160K105 17,801 -2,000 -10.10 3,626 -22.04 0.1538
2018-11-01 2018-09-30 13F Costco Wholesale COM 22160K105 19,801 250 1.28 4,651 13.83 0.1666
2018-07-26 2018-06-30 13F Costco Wholesale COM 22160K105 19,551 0 0.00 4,086 10.91 0.1557
2018-05-01 2018-03-31 13F Costco Wholesale COM 22160K105 19,551 -200 -1.01 3,684 0.22 0.1409
2018-01-30 2017-12-31 13F Costco Wholesale COM 22160K105 19,751 -20 -0.10 3,676 13.18 0.1353
2017-11-01 2017-09-30 13F Costco Wholesale COM 22160K105 19,771 185 0.94 3,248 3.70 0.1250
2017-07-27 2017-06-30 13F Costco Wholesale COM 22160K105 19,586 -325 -1.63 3,132 -6.20 0.1228
2017-05-01 2017-03-31 13F Costco Wholesale COM 22160K105 19,911 -5 -0.03 3,339 4.70 0.1356
2017-01-26 2016-12-31 13F Costco Wholesale COM 22160K105 19,916 -250 -1.24 3,189 3.67 0.1393
2016-11-02 2016-09-30 13F Costco Wholesale COM 22160K105 20,166 -660 -3.17 3,076 -5.96 0.1415
2016-08-01 2016-06-30 13F Costco Wholesale COM 22160K105 20,826 135 0.65 3,271 0.34 0.1529
2016-05-02 2016-03-31 13F Costco Wholesale COM 22160K105 20,691 0 0.00 3,260 -2.45 0.1630
2016-02-01 2015-12-31 13F Costco Wholesale COM 22160K105 20,691 300 1.47 3,342 13.36 0.1657
2015-10-23 2015-09-30 13F Costco Wholesale COM 22160K105 20,391 -32 -0.16 2,948 6.89 0.1459
2015-08-03 2015-06-30 13F Costco Wholesale COM 22160K105 20,423 -1,391 -6.38 2,758 -16.55 0.1232
2015-05-05 2015-03-31 13F Costco Wholesale COM 22160K105 21,814 21,814 3,305 0.1463
2015-02-04 2014-12-31 13F Costco Wholesale COM 22160K105 0 -22,255 -100.00 0 -100.00
2014-10-21 2014-09-30 13F Costco Wholesale COM 22160K105 22,255 -2,416 -9.79 2,789 -1.83 0.1216
2014-07-24 2014-06-30 13F Costco Wholesale COM 22160K105 24,671 -1,115 -4.32 2,841 -1.35 0.1208
2014-05-02 2014-03-31 13F Costco Wholesale COM 22160K105 25,786 -52,082 -66.88 2,880 -68.93 0.1292
2014-02-05 2013-12-31 13F Costco Wholesale COM 22160K105 77,868 -4,538 -5.51 9,268 -2.35 0.3316
2013-11-04 2013-09-30 13F Costco Wholesale COM 22160K105 82,406 -36,382 -30.63 9,491 -27.74 0.3715
2013-08-08 2013-06-30 13F Costco Wholesale COM 22160K105 118,788 118,788 13,134 0.4701
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2021-10-26 2021-09-30 13F COSTCO WHSL CORP COM Put 0 -100.00 0 n/a n/a n/a
2021-07-26 2021-06-30 13F COSTCO WHSL CORP COM Put 200 0 n/a n/a n/a
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.