PRIMECAP reports 5.88% Glaukos (NYSE: GKOS) ownership in new 13G filing

Rhea-AI Filing Summary

PRIMECAP Management Company has filed a Schedule 13G reporting beneficial ownership of Glaukos Corporation shares. PRIMECAP reports holding 3,376,928 shares, representing 5.88% of the class as of 12/31/2025. It has sole voting power over 3,374,178 shares and sole dispositive power over 3,376,928 shares.

The firm states that the securities were acquired and are held in the ordinary course of business and not for the purpose of changing or influencing control of Glaukos. The filing is signed by Deputy Chief Compliance Officer Jorge Antonio Rodriguez on behalf of PRIMECAP Management.

Insights

Institutional ownership analyst

PRIMECAP reports a 5.88% passive stake in Glaukos.

PRIMECAP Management Company discloses beneficial ownership of 3,376,928 Glaukos shares, equal to 5.88% of the class as of 12/31/2025. It holds sole voting power over 3,374,178 shares and sole dispositive power over the full 3,376,928 shares.

The Schedule 13G certification states the position is held in the ordinary course of business and is not intended to change or influence control of Glaukos. This characterizes PRIMECAP as a passive institutional holder rather than an activist.

The filing indicates a stable, sizeable institutional presence in the shareholder base, but does not describe any transactional changes, timing plans, or control intentions. Future ownership levels will be observable only through subsequent beneficial ownership filings if PRIMECAP’s percentage changes.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

Glaukos Corporation

(Name of Issuer)

COM

(Title of Class of Securities)

377322102

(CUSIP Number)

12/31/2025

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

SCHEDULE 13G

CUSIP No. 377322102

1

Names of Reporting Persons

PRIMECAP MANAGEMENT CO/CA/

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 3,374,178.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 3,376,928.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

3,376,928.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

5.88 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Glaukos Corporation
(b)	Address of issuer's principal executive offices: One Glaukos Way, Aliso Viejo, CALIFORNIA 92656
Item 2.
(a)	Name of person filing: PRIMECAP MANAGEMENT CO/CA/
(b)	Address or principal business office or, if none, residence: 177 EAST COLORADO BLVD. 11TH FLOOR PASADENA, California 91105
(c)	Citizenship: PRIMECAP MANAGEMENT CO/CA/ - UNITED STATES
(d)	Title of class of securities: COM
(e)	CUSIP No.: 377322102
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: 3,376,928
(b)	Percent of class: 5.88 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: PRIMECAP MANAGEMENT CO/CA/ - 3,374,178
	(ii) Shared power to vote or to direct the vote: PRIMECAP MANAGEMENT CO/CA/ - 0
	(iii) Sole power to dispose or to direct the disposition of: PRIMECAP MANAGEMENT CO/CA/ - 3,376,928
	(iv) Shared power to dispose or to direct the disposition of: PRIMECAP MANAGEMENT CO/CA/ - 0
Item 5.	Ownership of 5 Percent or Less of a Class.
	Not Applicable
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	Not Applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

PRIMECAP MANAGEMENT CO/CA/

Signature:	Jorge Antonio Rodriguez
Name/Title:	Deputy Chief Compliance Officer
Date:	02/10/2026

FAQ

How many Glaukos (GKOS) shares does PRIMECAP Management report owning?

PRIMECAP Management reports beneficial ownership of 3,376,928 Glaukos shares. The filing also notes sole voting power over 3,374,178 shares and sole dispositive power over all 3,376,928 shares, reflecting direct control over voting and disposition of this position.

What percentage of Glaukos (GKOS) does PRIMECAP Management own according to the Schedule 13G?

According to the Schedule 13G, PRIMECAP Management owns 5.88% of the outstanding class of Glaukos securities. This percentage is based on beneficial ownership of 3,376,928 shares as of December 31, 2025, crossing the 5% regulatory reporting threshold.

Is PRIMECAP Management’s Glaukos (GKOS) stake reported as passive or for control purposes?

PRIMECAP certifies its Glaukos stake is held in the ordinary course of business and not for changing or influencing control. The filing explicitly states the securities were not acquired and are not held in connection with any control-related transaction, consistent with a passive Schedule 13G filing.

What voting and dispositive powers does PRIMECAP Management have over its Glaukos (GKOS) shares?

PRIMECAP reports sole voting power over 3,374,178 shares and sole dispositive power over 3,376,928 shares. It reports no shared voting or shared dispositive power, indicating exclusive authority over how these shares are voted and whether they are sold or retained.

As of what date is PRIMECAP Management’s Glaukos (GKOS) ownership measured?

PRIMECAP’s ownership figures are measured as of December 31, 2025. The Schedule 13G identifies this as the date of the event requiring the filing, tying the 3,376,928 shares and 5.88% ownership figure to that specific measurement date.