Costco (COST) EVP Claudine Adamo sells 730 shares at $1003.021

Rhea-AI Filing Summary

Costco Wholesale Corporation executive Claudine Adamo reported an open-market sale of company stock. On March 9, 2026, the Executive Vice President sold 730 shares of Costco common stock at an average price of $1003.021 per share. After this transaction, she directly owns 6,121.195 Costco shares.

Insider Trade Summary

Net Seller: 730 shares ($732,205)

Net Sell 1 txn

Insider Adamo Claudine

Role Executive Vice President

Sold 730 shs ($732K)

Type	Security	Shares	Price	Value
Sale	Common Stock	730	$1,003.021	$732K

Holdings After Transaction: Common Stock — 6,121.195 shares (Direct)

Footnotes (1)

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Adamo Claudine

(Last) (First) (Middle)

999 LAKE DRIVE

(Street)

ISSAQUAH WA 98027

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
COSTCO WHOLESALE CORP /NEW [ COST ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Executive Vice President

3. Date of Earliest Transaction (Month/Day/Year)
03/09/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	03/09/2026		S		730	D	$1,003.021	6,121.195	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

	/s/ Alejandro Torres, Attorney-in-Fact	03/11/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction did Costco (COST) report for Claudine Adamo?

Costco reported that Executive Vice President Claudine Adamo completed an open-market sale of company stock. On March 9, 2026, she sold 730 shares of Costco common stock, as disclosed in a Form 4 insider trading report filed with regulators.

How many Costco (COST) shares did EVP Claudine Adamo sell?

Claudine Adamo sold 730 shares of Costco common stock. The transaction was an open-market sale executed on March 9, 2026, and is classified in the filing with transaction code “S,” which denotes a sale in the open market or a private transaction.

At what price were the Costco (COST) shares sold by Claudine Adamo?

The 730 Costco shares sold by Claudine Adamo were transacted at an average price of $1003.021 per share. This price reflects the weighted average sale price disclosed in the Form 4 for the March 9, 2026 open-market transaction in Costco common stock.

How many Costco (COST) shares does Claudine Adamo hold after the sale?

After the reported sale, Claudine Adamo directly holds 6,121.195 Costco shares. This post-transaction ownership figure is stated in the Form 4 and represents her remaining direct position in Costco common stock following the 730-share open-market sale on March 9, 2026.

Was the Claudine Adamo Costco (COST) transaction a buy or a sell?

The transaction reported for Claudine Adamo was a sale of Costco shares. The Form 4 classifies it with transaction code “S” and describes it as an open-market sale, showing 730 shares of Costco common stock sold at an average price of $1003.021 per share.

What role does Claudine Adamo hold at Costco (COST) in this insider filing?

In this insider trading report, Claudine Adamo is identified as an officer of Costco, serving as Executive Vice President. Her status as an executive officer is specified in the Form 4, which discloses her March 9, 2026 sale of 730 shares of Costco common stock.