Glaukos CDO reports tax-related share withholdings

Glaukos Corp Chief Development Officer Tomas Navratil reported routine tax-related share withholdings tied to restricted stock unit vesting.

Rhea-AI Filing Summary

Glaukos Corp Chief Development Officer Tomas Navratil reported routine tax-related share withholdings tied to restricted stock unit vesting. On March 23, 2026, 2,628 shares of common stock were withheld at $106.84 per share, leaving 71,003 shares directly held. On March 24, 2026, an additional 2,546 shares were withheld at $105.23 per share, leaving 68,457 shares directly held. These dispositions were made to satisfy tax withholding obligations on previously granted restricted stock units rather than as open-market sales. Footnotes state his holdings include 29,840 and 24,705 restricted stock units from prior grants that have not yet vested or been delivered.

Insider Trade Summary

Exercise Price or Tax Liability: 5,174 shares

Exercise Price or Tax Liability 2 txns

Insider Navratil Tomas

Role CHIEF DEVELOPMENT OFFICER

Type	Security	Shares	Price	Value
Exercise Price or Tax Liability	Common Stock	2,546	$105.23	$268K
Exercise Price or Tax Liability	Common Stock	2,628	$106.84	$281K

Holdings After Transaction: Common Stock — 68,457 shares (Direct)

Footnotes (4)

1. F1. 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. F2. Includes 29,840 restricted stock units that have not yet vested or been delivered to the Reporting Person.
3. F3. 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. F4. Includes 24,705 restricted stock units that have not yet vested or been delivered to the Reporting Person.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transaction did Glaukos (GKOS) CDO Tomas Navratil report?

Tomas Navratil reported tax-related share withholdings, not open-market trades. In two Form 4 entries, Glaukos withheld 5,174 common shares total to cover his tax obligations when restricted stock units vested and shares were delivered.

Were Tomas Navratil’s reported Glaukos (GKOS) transactions open-market sales?

No, they were not open-market sales. Both transactions were coded “F,” indicating shares were withheld by Glaukos to pay tax liabilities on vested restricted stock units, a routine compensation-related mechanism rather than discretionary selling in the market.

How many Glaukos (GKOS) shares were withheld for Tomas Navratil’s taxes?

A total of 5,174 Glaukos common shares were withheld. This includes 2,628 shares on March 23, 2026 at $106.84 per share and 2,546 shares on March 24, 2026 at $105.23 per share, all to satisfy tax withholding obligations.

How many Glaukos (GKOS) shares does Tomas Navratil hold after these transactions?

After the March 24, 2026 tax-withholding transaction, he directly holds 68,457 Glaukos common shares. Earlier, following the March 23, 2026 withholding event, his direct holdings were 71,003 shares, showing the impact of the second withholding.

What do the restricted stock unit footnotes mean for Glaukos (GKOS) CDO holdings?

The footnotes state his position includes restricted stock units from prior grants. Specifically, 29,840 RSUs from a March 22, 2023 grant and 24,705 RSUs from a March 24, 2022 grant have not yet vested or been delivered, representing additional potential future share deliveries.

How should investors interpret Form 4 code “F” in Glaukos (GKOS) insider filings?

Form 4 code “F” indicates shares used to pay tax or exercise costs, not standard selling. For Glaukos, this filing shows shares withheld by the company for Tomas Navratil’s tax obligations when his restricted stock units vested and converted into common shares.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Accepted by SEC EDGAR 03/25/2026 - 08:41 PM Learn about SEC filing dates

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^*

Navratil Tomas

(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)
	CHIEF DEVELOPMENT OFFICER

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		2,628(1)	D	$106.84	71,003(2)	D
Common Stock	03/24/2026		F		2,546(3)	D	$105.23	68,457(4)	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 29,840 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 24,705 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)