GLAUKOS (NYSE: GKOS) COO reports tax-withholding of 1,189 vested shares

Rhea-AI Filing Summary

GLAUKOS Corp’s President & COO Joseph E. Gilliam reported a routine tax-related share disposition. On the vesting of previously granted restricted stock units, 1,189 shares of common stock were withheld by the company to cover his tax obligations.

After this withholding, Gilliam directly holds 87,658 shares of GLAUKOS common stock, which the disclosure states includes 53,986 restricted stock units that are granted but not yet vested or delivered. This event reflects compensation and tax mechanics rather than an open‑market stock sale.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Gilliam Joseph E

Role PRESIDENT & COO

Type	Security	Shares	Price	Value
Tax Withholding	Common Stock	1,189	$98.94	$118K

Holdings After Transaction: Common Stock — 87,658 shares (Direct)

Footnotes (1)

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 14, 2024. Includes 53,986 restricted stock units that have not yet vested or been delivered to the Reporting Person.

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^*

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)
03/16/2026

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	03/16/2026		F		1,189(1)	D	$98.94	87,658(2)	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 14, 2024.

2. Includes 53,986 restricted stock units that have not yet vested or been delivered to the Reporting Person.

	Diana Scherer, Attorney-in-Fact	03/19/2026
	** 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 insider transaction did GLAUKOS (GKOS) President & COO Joseph Gilliam report?

Joseph Gilliam reported a tax-withholding disposition of 1,189 GLAUKOS shares. These shares were withheld by the company to satisfy tax obligations upon vesting of restricted stock units, not sold on the open market, indicating a routine compensation-related event.

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

The filing shows 1,189 shares of GLAUKOS common stock were withheld for Gilliam’s tax obligations. This occurred when restricted stock units vested and converted into shares, a standard mechanism for covering income-tax liabilities on equity compensation.

How many GLAUKOS (GKOS) shares does Joseph Gilliam hold after this transaction?

After the tax withholding, Joseph Gilliam directly holds 87,658 GLAUKOS shares. This total includes both already-delivered common stock and his remaining equity awards, providing context for the scale of the tax-related share disposition.

How many unvested restricted stock units does Joseph Gilliam have at GLAUKOS (GKOS)?

The disclosure states that Gilliam holds 53,986 restricted stock units that have not yet vested or been delivered. These unvested awards represent additional potential future share deliveries as vesting conditions are satisfied over time.

Was the GLAUKOS (GKOS) insider transaction an open-market sale of shares?

No. The transaction was a tax-withholding disposition, where shares were withheld by GLAUKOS to cover Joseph Gilliam’s tax obligations on vesting RSUs. It does not reflect an open-market sale decision by the executive.

What grant date is referenced for Joseph Gilliam’s GLAUKOS (GKOS) restricted stock units?

The footnote explains that the vested restricted stock units were originally granted on March 14, 2024. The 1,189 shares withheld relate to tax obligations arising when those units vested and were delivered as common stock.