Glaukos (GKOS) president sees 15,118 shares withheld to cover tax obligations

Rhea-AI Filing Summary

GLAUKOS Corp president and COO Joseph E. Gilliam reported routine share dispositions tied to tax withholding, not open-market sales. On March 23 and 24, 2026, a total of 15,118 shares of common stock were withheld by the company to cover his tax obligations upon restricted stock unit vesting. Following these transactions, he continues to hold 72,540 shares of common stock directly. Footnotes indicate his holdings also include unvested restricted stock units from prior grants.

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

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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^*

Gilliam Joseph E

(Last) (First) (Middle)

C/O GLAUKOS CORPORATION

ONE GLAUKOS WAY

(Street)

ALISO VIEJO CALIFORNIA 92656

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
GLAUKOS Corp [ GKOS ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	PRESIDENT & COO

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
03/23/2026

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

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

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

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	03/23/2026		F		2,804(1)	D	$106.84	84,854(2)	D
Common Stock	03/24/2026		F		4,926(3)	D	$105.23	79,928(4)	D
Common Stock	03/24/2026		F		7,388(3)	D	$105.23	72,540(5)	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:

1. Consists of shares withheld by the Issuer with respect to tax withholding obligations of the Reporting Person upon vesting and delivery of shares of common stock underlying restricted stock units previously granted by the Issuer on March 22, 2023.

2. Includes 48,787 restricted stock units that have not yet vested or been delivered to the Reporting Person.

3. Consists of shares withheld by the Issuer with respect to tax withholding obligations of the Reporting Person upon vesting and delivery of shares of common stock underlying restricted stock units previously granted by the Issuer on March 24, 2022.

4. Includes 39,725 restricted stock units that have not yet vested or been delivered to the Reporting Person.

5. Includes 26,133 restricted stock units that have not yet vested or been delivered to the Reporting Person.

	Diana Scherer, Attorney-in-Fact	03/25/2026
	** 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.
* Form 4: SEC 1474 (03-26)

FAQ

What did GLAUKOS (GKOS) executive Joseph Gilliam report in this Form 4?

Joseph Gilliam reported share dispositions related to tax withholding, not market sales. On March 23 and 24, 2026, 15,118 Glaukos common shares were withheld by the company to satisfy his tax obligations when previously granted restricted stock units vested.

How many GLAUKOS (GKOS) shares were withheld for Joseph Gilliam’s taxes?

A total of 15,118 Glaukos common shares were withheld to cover Joseph Gilliam’s tax obligations. The Form 4 shows three Code F transactions, each reflecting withholding upon the vesting and delivery of shares underlying earlier restricted stock unit awards.

Are Joseph Gilliam’s GLAUKOS (GKOS) transactions open-market sales?

No, the transactions are not open-market sales. They are Code F tax-withholding dispositions, where Glaukos withheld shares to pay Joseph Gilliam’s tax liabilities associated with vested restricted stock units previously granted under the company’s equity compensation program.

How many GLAUKOS (GKOS) shares does Joseph Gilliam hold after these transactions?

After the reported tax-withholding dispositions, Joseph Gilliam directly holds 72,540 Glaukos common shares. Footnotes also state that his holdings include additional restricted stock units that have not yet vested or been delivered under earlier equity awards.

What do the restricted stock unit footnotes in the GLAUKOS (GKOS) Form 4 indicate?

The footnotes explain that the withheld shares relate to restricted stock units granted in March 2022 and March 2023. They also note that Joseph Gilliam’s position includes unvested restricted stock units, which may convert into additional Glaukos common shares once vesting and delivery conditions are met.