Disciplined Growth owns 11.3% stake in Proto Labs (PRLB)

Rhea-AI Filing Summary

Disciplined Growth Investors, Inc. filed an amended Schedule 13G reporting its ownership in Proto Labs Inc12/31/2025, it beneficially owned 2,673,729 shares of Proto Labs common stock, representing 11.3% of the class.

The firm has sole voting power over 2,398,250 shares and sole dispositive power over 2,673,729 shares, with no shared voting or dispositive power. It certifies the shares were acquired and are held in the ordinary course of business and not for the purpose of changing or influencing control of Proto Labs.

02/17/2026 - 04:38 PM

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 7)

Proto Labs Inc

(Name of Issuer)

Common Stock

(Title of Class of Securities)

743713109

(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. 743713109

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 2,398,250.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 2,673,729.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

2,673,729.00

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)

11.3 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Proto Labs Inc
(b)	Address of issuer's principal executive offices: 5540 Pioneer Creek, 5540 Pioneer Creek, Maple Plain, MINNESOTA, 55359.
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 Stock
(e)	CUSIP No.: 743713109
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: 2,673,729
(b)	Percent of class: 11.3%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 2,398,250
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 2,673,729
	(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:	02/17/2026

FAQ

How much of Proto Labs (PRLB) stock does Disciplined Growth Investors own?

Disciplined Growth Investors beneficially owns 2,673,729 shares of Proto Labs common stock, representing 11.3% of the class. This ownership level is disclosed as of December 31, 2025 in the amended Schedule 13G filing.

What type of SEC filing did Disciplined Growth Investors submit for Proto Labs (PRLB)?

Disciplined Growth Investors submitted an amended Schedule 13G/A for Proto Labs. This filing reports passive ownership of more than 5% of a company’s shares, indicating investment purposes rather than an attempt to influence corporate control.

Does Disciplined Growth Investors seek to influence control of Proto Labs (PRLB)?

According to the certification, the shares were acquired and are held in the ordinary course of business and not for changing or influencing control of Proto Labs. The filing also says they are not held in connection with any control-related transaction.

What voting power does Disciplined Growth Investors have over Proto Labs (PRLB) shares?

Disciplined Growth Investors reports sole voting power over 2,398,250 shares of Proto Labs common stock and no shared voting power. This means it alone can vote those shares, based on the Schedule 13G ownership breakdown.

What dispositive power does Disciplined Growth Investors report for Proto Labs (PRLB)?

The firm reports sole dispositive power over 2,673,729 shares and no shared dispositive power. Sole dispositive power means Disciplined Growth Investors alone determines whether and how those Proto Labs shares may be sold or otherwise disposed of.

When did the Proto Labs (PRLB) ownership level trigger this Schedule 13G/A filing?

The filing lists 12/31/2025 as the date of event requiring the statement. That date reflects when the reported ownership position met the reporting criteria, leading to this amended Schedule 13G submission.