[SCHEDULE 13G/A] Allegro MicroSystems, Inc. SEC Filing

Rhea-AI Filing Summary

Capital Research Global Investors reported beneficial ownership of 15,904,357 shares of Allegro MicroSystems, representing 8.6% of the 184,925,395 shares believed to be outstanding. The filing identifies CRGI as a division of Capital Research and Management Company and related investment management entities that provide services under the name "Capital Research Global Investors."

The statement indicates CRGI has sole voting and sole dispositive power over these shares and certifies the securities are held in the ordinary course of business and not for the purpose of changing or influencing control of Allegro.

Positive

• Material institutional stake: 15,904,357 shares representing 8.6% of outstanding stock
• Sole voting and dispositive power: filer reports exclusive authority to vote and dispose of these shares
• Ordinary-course holding: filer certifies shares are held in the ordinary course and not to change issuer control

Negative

• None.

Insights

Financial Analyst

TL;DR: A material institutional stake of 8.6% signals significant investor interest; the filer reports sole control and no intent to seek control.

The filing discloses a meaningful position by an established asset manager: 15,904,357 shares or 8.6% of Allegro's outstanding shares. CRGI is presented as an investment management division of Capital Research and Management Company and related entities, and the form records sole voting and dispositive authority. The filer also certifies the shares are held in the ordinary course and not to influence control, which limits immediate governance implications while confirming concentrated institutional ownership.

Corporate Governance Expert

TL;DR: Significant single-investor disclosure with sole power noted; certification denies intent to alter control, so no immediate governance action is signaled.

This Schedule 13G/A shows a substantial passive position by Capital Research Global Investors. The form records sole voting and dispositive power over 15,904,357 shares and explicitly states the holdings are not aimed at changing issuer control. From a governance perspective, the filing is material because it documents concentrated ownership that could matter in future votes, but the certification reduces the likelihood of imminent activist or control initiatives based on the information provided.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

Allegro MicroSystems, Inc.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

01749D105

(CUSIP Number)

06/30/2025

(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. 01749D105

1

Names of Reporting Persons

Capital Research Global Investors

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

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 15,904,357.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 15,904,357.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

15,904,357.00

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)

8.6 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Allegro MicroSystems, Inc.
(b)	Address of issuer's principal executive offices: 955 PERIMETER ROAD, MANCHESTER, NH 03103
Item 2.
(a)	Name of person filing: Capital Research Global Investors
(b)	Address or principal business office or, if none, residence: 333 South Hope Street, 55th Fl, Los Angeles, CA 90071
(c)	Citizenship: N/A
(d)	Title of class of securities: Common Stock
(e)	CUSIP No.: 01749D105
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: 15,904,357 ** **Capital Research Global Investors ("CRGI") is a division of Capital Research and Management Company ("CRMC"), as well as its investment management subsidiaries and affiliates Capital Bank and Trust Company, Capital International, Inc., Capital International Limited, Capital International Sarl, Capital International K.K., Capital Group Private Client Services, Inc., and Capital Group Investment Management Private Limited (together with CRMC, the "investment management entities"). CRGI's divisions of each of the investment management entities collectively provide investment management services under the name "Capital Research Global Investors." CRGI is deemed to be the beneficial owner of 15,904,357 shares or 8.6% of the 184,925,395 shares believed to be outstanding.
(b)	Percent of class: 8.6 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 15,904,357
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 15,904,357
	(iv) Shared power to dispose or to direct the disposition of: 0
Item 5.	Ownership of 5 Percent or Less of a Class.
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. SMALLCAP World Fund, Inc.
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.

Capital Research Global Investors

Signature:	Jae Won Chung
Name/Title:	Vice President and Senior Counsel II, Capital Research and Management Company
Date:	08/05/2025

FAQ

What stake does Capital Research Global Investors hold in ALGM?

Capital Research Global Investors beneficially owns 15,904,357 shares, equal to 8.6% of 184,925,395 shares believed outstanding.

Who filed the Schedule 13G/A for ALGM?

The filing was submitted by Capital Research Global Investors, a division of Capital Research and Management Company and related investment management entities.

Does the filer have voting or dispositive power over the ALGM shares?

Yes. The filing states the filer has sole power to vote and sole power to dispose of the 15,904,357 shares.

Is the ownership intended to influence control of Allegro MicroSystems (ALGM)?

The filer certifies the securities are held in the ordinary course of business and were not acquired to change or influence control of the issuer.

How is the filer classified under the Schedule 13G/A?

The filer is classified as an IA (investment adviser) in the filing.