Disciplined Growth Investors owns 10.7% of Core Labs

Core Laboratories Inc. ownership disclosure: Disciplined Growth Investors, Inc. reports beneficial ownership of 4,937,115 common shares of Core Laboratories Inc., representing 10.7% of the class.

Rhea-AI Filing Summary

Core Laboratories Inc. ownership disclosure: Disciplined Growth Investors, Inc. reports beneficial ownership of 4,937,115 common shares of Core Laboratories Inc., representing 10.7% of the class. The filer reports sole voting power over 4,653,638 shares and sole dispositive power over 4,937,115 shares. The filing is signed by Peter G. Rieke on 05/15/2026.

Insights

Institutional Ownership Analyst

Large passive stake disclosed by an institutional holder.

Disciplined Growth Investors reports beneficial ownership of 4,937,115 shares, equal to 10.7% of the outstanding common stock. The filing lists sole voting power of 4,653,638 shares and sole dispositive power of 4,937,115.

This is a snapshot of position size and control metrics; subsequent filings will show any changes in voting or disposition. Timing and cash‑flow treatment are not stated in the provided excerpt.

Securities Compliance Specialist

Form amendment aligns ownership reporting requirements under Section 13.

The amendment updates a Schedule 13G/A entry for Core Laboratories, providing precise counts for voting and dispositive powers and the 05/15/2026 signature. It conforms to disclosure mechanics for institutional investors.

Filings of this type are routine regulatory disclosures; any change in ownership or voting intent would require further amendments.

Key Figures

Beneficial ownership: 4,937,115 shares Percent of class: 10.7% Sole voting power: 4,653,638 shares +3 more

6 metrics

Beneficial ownership 4,937,115 shares reported on Schedule 13G/A

Percent of class 10.7% percent of common shares outstanding

Sole voting power 4,653,638 shares shares with sole power to vote

Sole dispositive power 4,937,115 shares shares with sole power to dispose

Signature date 05/15/2026 filing signed by Peter G. Rieke

CUSIP 21867A105 Core Laboratories common shares CUSIP

Key Terms

beneficially owned, sole dispositive power, Schedule 13G/A

3 terms

beneficially owned regulatory

"Amount beneficially owned: 4,937,115"

Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.

sole dispositive power regulatory

"Sole power to dispose or to direct the disposition of: 4,937,115"

Sole dispositive power is the exclusive legal authority to decide what happens to a security — for example, whether to sell, transfer, or retain shares — without needing anyone else’s permission. Investors care because it signals who truly controls the economic outcome of an investment: like holding the only key to a safe, the holder can realize gains or losses and may trigger regulatory reporting, insider rules, or influence over corporate ownership.

Schedule 13G/A regulatory

"Form type indicated as SCHEDULE 13G/A (Amendment No. 6)"

A Schedule 13G/A is an amended public filing with the U.S. securities regulator that updates a previous Schedule 13G, disclosing when an individual or group holds a substantial (typically over 5%) stake in a company and is claiming a passive, non‑controlling intent. Investors monitor these updates because rising or falling holdings can signal changing confidence, potential future moves, or shifts in voting power — like watching a public ledger where large shareholders quietly adjust their positions.

FAQ

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

What stake does Disciplined Growth Investors hold in Core Laboratories (CLB)?

Disciplined Growth Investors reports beneficial ownership of 4,937,115 shares, representing 10.7% of Core Laboratories' common stock. The filing lists sole voting power over 4,653,638 shares and sole dispositive power over 4,937,115 shares.

What is a Schedule 13G/A amendment for CLB?

A Schedule 13G/A amendment updates an earlier institutional ownership disclosure; it reports current beneficial ownership quantities and voting/dispositive powers. This amendment records the holder's position and is signed by the filer on 05/15/2026 for Core Laboratories.

Does the filing indicate Disciplined Growth Investors will sell CLB shares?

The filing lists voting and dispositive powers but does not state any planned sales or transfers. It only reports current beneficial ownership counts and control metrics; no sale instructions or proceeds treatment appear in the provided excerpt.

Who certified the Schedule 13G/A for CLB and when?

The filing is signed by Peter G. Rieke, Chief Operating & Compliance Officer of Disciplined Growth Investors, with signature date 05/15/2026. The header includes the date 03/31/2026 associated with the reporting period.

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

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Accepted by SEC EDGAR 05/15/2026 - 04:10 PM EDT Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 6)

Core Laboratories Inc. /DE/

(Name of Issuer)

Common Shares

(Title of Class of Securities)

21867A105

(CUSIP Number)

03/31/2026

(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)

schemaVersion:

SCHEDULE 13G

CUSIP Number(s): 21867A105

1

Names of Reporting Persons

DISCIPLINED GROWTH INVESTORS INC /MN

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

MINNESOTA

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 4,653,638.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 4,937,115.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

4,937,115.00

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)

10.7 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Core Laboratories Inc. /DE/
(b)	Address of issuer's principal executive offices: 6316 WINDFERN ROAD, 6316 WINDFERN ROAD, HOUSTON, TEXAS, 77040.
Item 2.
(a)	Name of person filing: Disciplined Growth Investors, Inc.
(b)	Address or principal business office or, if none, residence: 150 South Fifth Street, Suite 2550 Minneapolis, MN 55402
(c)	Citizenship: Minnesota, USA
(d)	Title of class of securities: Common Shares
(e)	CUSIP No.: 21867A105
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: 4,937,115
(b)	Percent of class: 10.7%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 4,653,638
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 4,937,115
	(iv) Shared power to dispose or to direct the disposition of: 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.

DISCIPLINED GROWTH INVESTORS INC /MN

Signature:	Peter G. Rieke
Name/Title:	Chief Operating & Compliance Officer
Date:	05/15/2026