Costco Wholesale Corporation
MX ˙ BMV ˙ US22160K1051
SecurityMX:COST / Costco Wholesale Corporation
InstitutionAmbassador Advisors, LLC
Latest Disclosed Ownership4,146 shares
Latest Disclosed Value $ 4,130,964
Ambassador Advisors, LLC reports 143.17% increase in ownership of COST / Costco Wholesale Corporation

On April 17, 2026 - Ambassador Advisors, LLC filed a 13F-HR form disclosing ownership of 4,146 shares of Costco Wholesale Corporation (MX:COST) valued at $4,130,964 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 1,705 shares of Costco Wholesale Corporation. This represents a change in shares of 143.17% 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)
2026-04-17 2026-03-31 13F COSTCO WHOLESALE COM 22160K105 4,146 2,441 143.17 4,131 180.95 0.5894
2026-02-13 2025-12-31 13F COSTCO WHSL CORP COM 22160K105 1,705 -2,898 -62.96 1,471 -65.49 0.2156
2025-11-19 2025-09-30 13F COSTCO WHSL CORP COM 22160K105 4,603 -1 -0.02 4,261 -6.52 0.6336
2025-08-14 2025-06-30 13F COSTCO WHSL CORP COM 22160K105 4,604 -180 -3.76 4,558 0.73 0.7073
2025-05-16 2025-03-31 13F COSTCO WHSL CORP COM 22160K105 4,784 -114 -2.33 4,525 0.82 0.7878
2025-02-13 2024-12-31 13F COSTCO WHSL CORP COM 22160K105 4,898 205 4.37 4,488 7.86 0.7641
2024-11-14 2024-09-30 13F COSTCO WHSL CORP COM 22160K105 4,693 2,416 106.10 4,160 114.99 0.7238
2024-08-14 2024-06-30 13F COSTCO WHSL CORP COM 22160K105 2,277 76 3.45 1,935 20.04 0.3500
2024-05-15 2024-03-31 13F COSTCO WHSL CORP COM 22160K105 2,201 484 28.19 1,613 32.02 0.2927
2024-02-15 2023-12-31 13F COSTCO WHSL CORP COM 22160K105 1,717 16 0.94 1,221 24.21 0.2710
2023-11-15 2023-09-30 13F COSTCO WHSL CORP COM 22160K105 1,701 145 9.32 984 12.21 0.2395
2023-08-15 2023-06-30 13F COSTCO WHSL CORP COM 22160K105 1,556 -137 -8.09 876 3.18 0.2021
2023-05-15 2023-03-31 13F COSTCO WHSL CORP COM 22160K105 1,693 433 34.37 850 47.65 0.1925
2023-02-14 2022-12-31 13F COSTCO WHSL CORP COM 22160K105 1,260 312 32.91 575 28.35 0.1250
2022-11-18 2022-09-30 13F/A-1 COSTCO WHSL CORP COM 22160K105 948 -35 -3.56 448 -4.88 0.1062
2022-11-14 2022-09-30 13F COSTCO WHSL CORP COM 22160K105 983 0 472 0.0980
2022-08-12 2022-06-30 13F COSTCO WHSL CORP COM 22160K105 983 -13 -1.31 471 -17.80 0.1057
2022-05-16 2022-03-31 13F COSTCO WHSL CORP COM 22160K105 996 -6 -0.60 573 0.70 0.1111
2022-02-14 2021-12-31 13F COSTCO WHSL CORP COM 22160K105 1,002 -645 -39.16 569 -23.11 0.1080
2021-11-16 2021-09-30 13F COSTCO WHSL CORP COM 22160K105 1,647 -414 -20.09 740 -9.31 0.1435
2021-08-16 2021-06-30 13F COSTCO WHSL CORP COM 22160K105 2,061 -2,770 -57.34 816 -52.08 0.1617
2021-05-13 2021-03-31 13F COSTCO WHSL CORP COM 22160K105 4,831 -10,323 -68.12 1,703 -70.18 0.3807
2021-02-17 2020-12-31 13F COSTCO WHSL CORP COM 22160K105 15,154 -3,261 -17.71 5,710 -12.65 2.4910
2020-11-13 2020-09-30 13F COSTCO WHSL CORP COM 22160K105 18,415 -2,650 -12.58 6,537 2.35 1.5823
2020-08-13 2020-06-30 13F COSTCO WHSL CORP COM 22160K105 21,065 -3,535 -14.37 6,387 -8.94 1.6571
2020-05-12 2020-03-31 13F COSTCO WHSL CORP COM 22160K105 24,600 15,639 174.52 7,014 166.29 1.9753
2020-01-22 2019-12-31 13F COSTCO WHSL CORP COM 22160K105 8,961 8,961 2,634 0.6194
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.