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Glaukos (GKOS) CDO reports 483-share tax withholding, holds 88,350 shares

Filing Impact
(Neutral)
Filing Sentiment
(Neutral)
Form Type
4

Rhea-AI Filing Summary

GLAUKOS Corp Chief Development Officer Tomas Navratil reported a small share disposition related to tax withholding, not a market sale. On this Form 4, 483 shares of common stock were withheld by the company at $142.57 per share to satisfy tax obligations upon vesting of restricted stock units granted on March 18, 2021.

After this tax-withholding event, Navratil directly holds 88,350 shares of GLAUKOS common stock, which the filing notes include 38,817 restricted stock units that have not yet vested or been delivered. This filing reflects a routine compensation and tax event rather than an open-market trade.

Positive

  • None.

Negative

  • None.
Insider Navratil Tomas
Role CHIEF DEVELOPMENT OFFICER
Type Security Shares Price Value
Tax Withholding Common Stock 483 $142.57 $69K
Holdings After Transaction: Common Stock — 88,350 shares (Direct, null)
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 18, 2021. Includes 38,817 restricted stock units that have not yet vested or been delivered to the Reporting Person.
Shares withheld for taxes 483 shares Common stock disposed via tax withholding on 2026-06-25
Price per share for withholding $142.57 per share Valuation used for 483-share tax-withholding disposition
Shares held after transaction 88,350 shares Total direct GLAUKOS common stock holdings following Form 4 transaction
Unvested restricted stock units 38,817 RSUs Restricted stock units not yet vested or delivered to Tomas Navratil
restricted stock units financial
"delivery of shares of common stock underlying restricted stock units previously granted"
Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.
tax withholding obligations financial
"shares withheld by the Issuer with respect to tax withholding obligations of the Reporting Person"
vesting financial
"upon vesting and delivery of shares of common stock underlying restricted stock units"
Vesting is the process by which you earn full ownership of something, like company stock or a retirement benefit, over time. It’s like earning the right to keep a gift piece by piece the longer you stay with a company, making sure employees stay committed before they receive all the benefits.
Form 4 regulatory
"On this Form 4, 483 shares of common stock were withheld"
Form 4 is a official document that company insiders, such as executives or major shareholders, file with regulators whenever they buy or sell company shares. It provides transparency about how those with inside knowledge are trading, helping investors see if insiders are confident in the company's prospects or may be selling for personal reasons. This information can influence investor decisions by revealing insiders' perspectives on the company's value.
payment of exercise price or tax liability by delivering securities regulatory
"transaction code description: Payment of exercise price or tax liability by delivering securities"
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Form 4 Insider Transactions: What Each Field Means →
SEC Form 4
FORM 4UNITED 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)
Director10% Owner
XOfficer (give title below)Other (specify below)
CHIEF DEVELOPMENT OFFICER
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
06/25/2026		6. Individual or Joint/Group Filing (Check Applicable Line)
XForm 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)
CodeVAmount(A) or (D)Price
Common Stock06/25/2026F483(1)D$142.5788,350(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)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount 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 18, 2021.
2. Includes 38,817 restricted stock units that have not yet vested or been delivered to the Reporting Person.
Diana Scherer, Attorney-in-Fact06/29/2026
** Signature of Reporting PersonDate
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)

Source: View Original Filing on SEC EDGAR

FAQ

What insider transaction did GLAUKOS (GKOS) report for Tomas Navratil?

GLAUKOS reported that Chief Development Officer Tomas Navratil had 483 shares of common stock withheld. The shares were retained by the company to cover tax obligations tied to vesting restricted stock units granted on March 18, 2021, not sold on the open market.

Was the GLAUKOS (GKOS) Form 4 transaction a sale of shares by Tomas Navratil?

The Form 4 does not show an open-market sale by Tomas Navratil. Instead, 483 shares were disposed of through tax withholding, where the issuer kept shares to satisfy tax liabilities from vesting restricted stock units granted as equity compensation.

How many GLAUKOS (GKOS) shares does Tomas Navratil hold after this Form 4?

Following the reported tax-withholding disposition, Tomas Navratil directly holds 88,350 shares of GLAUKOS common stock. This total includes both currently held shares and equity awards, providing a snapshot of his ongoing ownership stake after the compensation-related transaction.

What role do restricted stock units play in Tomas Navratil’s GLAUKOS (GKOS) holdings?

Navratil’s holdings include 38,817 restricted stock units that have not yet vested or been delivered. These RSUs represent future potential shares, which will convert into common stock over time as vesting conditions specified in prior equity grants are satisfied.

What does transaction code "F" mean in the GLAUKOS (GKOS) Form 4 for Tomas Navratil?

Transaction code "F" indicates payment of a tax liability using company stock. In this filing, 483 GLAUKOS shares were withheld by the issuer to cover Navratil’s tax obligations arising from the vesting and delivery of previously granted restricted stock units.

How is the $142.57 price per share used in the GLAUKOS (GKOS) Form 4 transaction?

The Form 4 lists a price of $142.57 per share for the 483 shares disposed. This figure is used to value the stock withheld for tax purposes when restricted stock units vested, rather than representing a price at which shares were sold in the open market.