Costco Wholesale Corporation
MX ˙ BMV ˙ US22160K1051
SecurityMX:COST / Costco Wholesale Corporation
InstitutionNorthern Trust Corp
Latest Disclosed Ownership4,928,107 shares
Latest Disclosed Value $ 4,910,513,658
Northern Trust Corp reports 0.29% increase in ownership of COST / Costco Wholesale Corporation

On May 14, 2026 - Northern Trust Corp filed a 13F-HR form disclosing ownership of 4,928,107 shares of Costco Wholesale Corporation (MX:COST) valued at $4,910,513,658 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 4,913,721 shares of Costco Wholesale Corporation. This represents a change in shares of 0.29% during the quarter.

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)
2026-05-14 2026-03-31 13F COSTCO WHOLESALE COM 22160K105 4,928,107 14,386 0.29 4,910,514 15.89 0.6490
2026-02-17 2025-12-31 13F COSTCO WHSL CORP COM 22160K105 4,913,721 -146,269 -2.89 4,237,298 -9.53 0.5402
2025-11-14 2025-09-30 13F COSTCO WHSL CORP COM 22160K105 5,059,990 5,438 0.11 4,683,679 -6.40 0.5992
2025-08-13 2025-06-30 13F COSTCO WHSL CORP COM 22160K105 5,054,552 -54,543 -1.07 5,003,703 3.55 0.6881
2025-05-13 2025-03-31 13F COSTCO WHSL CORP COM 22160K105 5,109,095 -148,714 -2.83 4,832,080 0.30 0.7174
2025-02-14 2024-12-31 13F COSTCO WHSL CORP COM 22160K105 5,257,809 587,303 12.57 4,817,573 16.35 0.6821
2024-11-13 2024-09-30 13F COSTCO WHSL CORP COM 22160K105 4,670,506 -153,204 -3.18 4,140,497 0.99 0.6778
2024-08-14 2024-06-30 13F COSTCO WHSL CORP COM 22160K105 4,823,710 -19,624 -0.41 4,100,105 15.55 0.6909
2024-05-14 2024-03-31 13F COSTCO WHSL CORP COM 22160K105 4,843,334 -175,566 -3.50 3,548,372 7.11 0.6131
2024-02-13 2023-12-31 13F COSTCO WHSL CORP COM 22160K105 5,018,900 -116,047 -2.26 3,312,876 14.20 0.5997
2023-11-13 2023-09-30 13F COSTCO WHSL CORP COM 22160K105 5,134,947 210,586 4.28 2,901,040 9.42 0.5619
2023-08-11 2023-06-30 13F COSTCO WHSL CORP COM 22160K105 4,924,361 -227,218 -4.41 2,651,177 3.58 0.5095
2023-05-15 2023-03-31 13F COSTCO WHSL CORP COM 22160K105 5,151,579 212,617 4.30 2,559,665 13.53 0.5075
2023-02-13 2022-12-31 13F COSTCO WHSL CORP COM 22160K105 4,938,962 -37,516 -0.75 2,254,636 -4.07 0.4731
2022-11-14 2022-09-30 13F COSTCO WHSL CORP COM 22160K105 4,976,478 -65,092 -1.29 2,350,241 -2.73 0.5369
2022-08-12 2022-06-30 13F COSTCO WHSL CORP COM 22160K105 5,041,570 -148,565 -2.86 2,416,324 -19.15 0.5176
2022-05-13 2022-03-31 13F COSTCO WHSL CORP COM 22160K105 5,190,135 -222,342 -4.11 2,988,738 -2.73 0.5258
2022-02-08 2021-12-31 13F COSTCO WHSL CORP COM 22160K105 5,412,477 -313,059 -5.47 3,072,662 19.43 0.5034
2021-11-15 2021-09-30 13F COSTCO WHSL CORP COM 22160K105 5,725,536 -179,238 -3.04 2,572,769 10.12 0.4554
2021-08-13 2021-06-30 13F COSTCO WHSL CORP COM 22160K105 5,904,774 -132,106 -2.19 2,336,342 9.80 0.4115
2021-05-12 2021-03-31 13F COSTCO WHSL CORP COM 22160K105 6,036,880 18,941 0.31 2,127,880 -6.15 0.3958
2021-02-11 2020-12-31 13F COSTCO WHSL CORP COM 22160K105 6,017,939 -163,753 -2.65 2,267,440 3.32 0.4417
2020-11-16 2020-09-30 13F COSTCO WHSL CORP COM 22160K105 6,181,692 97,213 1.60 2,194,501 18.95 0.4812
2020-08-14 2020-06-30 13F COSTCO WHSL CORP COM 22160K105 6,084,479 69,360 1.15 1,844,876 7.57 0.4371
2020-05-14 2020-03-31 13F COSTCO WHSL CORP COM 22160K105 6,015,119 -60,927 -1.00 1,715,092 -3.96 0.4924
2020-02-14 2019-12-31 13F COSTCO WHSL CORP COM 22160K105 6,076,046 -104,636 -1.69 1,785,872 0.29 0.3997
2019-11-13 2019-09-30 13F COSTCO WHSL CORP COM 22160K105 6,180,682 -198,513 -3.11 1,780,717 5.63 0.4263
2019-08-13 2019-06-30 13F COSTCO WHSL CORP COM 22160K105 6,379,195 60,035 0.95 1,685,767 10.17 0.3999
2019-05-13 2019-03-31 13F COSTCO WHSL CORP COM 22160K105 6,319,160 88,456 1.42 1,530,120 20.55 0.3779
2019-02-12 2018-12-31 13F COSTCO WHSL CORP COM 22160K105 6,230,704 202,554 3.36 1,269,257 -10.36 0.3560
2018-11-14 2018-09-30 13F COSTCO WHSL CORP COM 22160K105 6,028,150 -201,239 -3.23 1,415,892 8.76 0.3465
2018-09-18 2018-06-30 13F/A-1 COSTCO WHSL CORP COM 22160K105 6,229,389 37,778 0.61 1,301,817 11.58 0.3306
2018-08-14 2018-06-30 13F COSTCO WHSL CORP COM 22160K105 6,258,309 66,698 1,307,861
2018-05-09 2018-03-31 13F COSTCO WHSL CORP COM 22160K105 6,191,611 -142,928 -2.26 1,166,686 -1.04 0.3035
2018-02-14 2017-12-31 13F COSTCO WHSL CORP COM 22160K105 6,334,539 -202,714 -3.10 1,178,985 9.77 0.2986
2017-11-13 2017-09-30 13F COSTCO WHSL CORP COM 22160K105 6,537,253 22,958 0.35 1,074,004 3.09 0.2799
2017-08-11 2017-06-30 13F COSTCO WHSL CORP COM 22160K105 6,514,295 156,901 2.47 1,041,831 -2.27 0.2913
2017-05-12 2017-03-31 13F COSTCO WHSL CORP COM 22160K105 6,357,394 295,368 4.87 1,066,073 9.84 0.3074
2017-02-13 2016-12-31 13F COSTCO WHSL CORP COM 22160K105 6,062,026 -167,543 -2.69 970,592 2.16 0.2977
2016-11-09 2016-09-30 13F COSTCO WHSL CORP COM 22160K105 6,229,569 -34,058 -0.54 950,071 -3.41 0.2959
2016-08-12 2016-06-30 13F COSTCO WHSL CORP COM 22160K105 6,263,627 -87,455 -1.38 983,641 -1.32 0.3193
2016-08-19 2016-03-31 13F/A-1 COSTCO WHSL CORP COM 22160K105 6,351,082 -38,586 -0.60 996,753 -3.41 0.3306
2016-05-13 2016-03-31 13F Costco Whsl Corp COMM 22160K105 6,351,058 1,000,799
2016-02-12 2015-12-31 13F Costco Whsl Corp COMM 22160K105 6,389,668 -496,744 -7.21 1,031,931 3.65 0.3421
2015-11-12 2015-09-30 13F Costco Whsl Corp COMM 22160K105 6,886,412 185,758 2.77 995,568 10.01 0.3322
2015-08-13 2015-06-30 13F COSTCO WHSL CORP COM 22160K105 6,700,654 -236,139 -3.40 904,990 -13.88 0.6135
2015-08-13 2015-06-30 13F Costco Whsl Corp COMM 022160K10 317,647 -6,619,146 42,901 0.0291
2015-05-14 2015-03-31 13F Costco Whsl Corp COMM 22160K105 6,936,793 -115,209 -1.63 1,050,890 5.13 0.3161
2015-02-12 2014-12-31 13F Costco Whsl Corp COM 22160K105 7,052,002 16,340 0.23 999,622 13.37 0.3018
2014-11-13 2014-09-30 13F Costco Whsl Corp COMM 22160K105 7,035,662 -60,956 -0.86 881,708 7.89 0.2769
2014-08-14 2014-06-30 13F COSTCO WHSL CORP com 22160K105 7,096,618 -152,180 -2.10 817,246 0.95 0.2547
2014-05-14 2014-03-31 13F COSTCO WHSL CORP COM 22160K105 7,248,798 -58,684 -0.80 809,547 -6.92 0.2547
2014-02-21 2013-12-31 13F/A-1 COSTCO WHSL CORP COM 22160K105 7,307,482 -103,985 -1.40 869,736 1.89 0.2789
2014-02-12 2013-12-31 13F COSTCO WHSL CORP COM 22160K105 7,307,482 869,736
2013-11-13 2013-09-30 13F COSTCO WHSL CORP COM 22160K105 7,411,467 -589,400 -7.37 853,579 -3.51 0.3006
2013-08-09 2013-06-30 13F COSTCO WHSL CORP COM 22160K105 8,000,867 8,000,867 884,656 0.3206
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.