William Blair reports 3.4% Amicus Therapeutics (FOLD) ownership stake

Rhea-AI Filing Summary

Amicus Therapeutics, Inc. received an amended Schedule 13G from William Blair Investment Management, LLC reporting its beneficial ownership of the company’s common stock. William Blair reports beneficial ownership of 10,627,717 shares of Amicus common stock, representing 3.4% of the outstanding shares as of 12/31/2025.

The firm has sole power to vote 10,321,526 shares and sole power to dispose of 10,627,717 shares, with no shared voting or dispositive power. William Blair certifies that the shares were acquired and are held in the ordinary course of business and not for the purpose of changing or influencing control of Amicus Therapeutics.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

AMICUS THERAPEUTICS, INC.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

03152W109

(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. 03152W109

1

Names of Reporting Persons

WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC

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 10,321,526.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 10,627,717.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

10,627,717.00

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)

3.4 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

Item 1.
(a)	Name of issuer: AMICUS THERAPEUTICS, INC.
(b)	Address of issuer's principal executive offices: 47 HULFISH STREET, 47 HULFISH STREET, PRINCETON, NEW JERSEY, 08542.
Item 2.
(a)	Name of person filing: William Blair Investment Management, LLC
(b)	Address or principal business office or, if none, residence: 150 North Riverside Plaza, Chicago, IL 60606
(c)	Citizenship: Delaware
(d)	Title of class of securities: Common Stock
(e)	CUSIP No.: 03152W109
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: 10,627,717
(b)	Percent of class: 3.4%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 10,321,526
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 10,627,717
	(iv) Shared power to dispose or to direct the disposition of: 0
Item 5.	Ownership of 5 Percent or Less of a Class.
	Ownership of 5 percent or less of a class
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.

WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC

Signature:	Telmo Martins
Name/Title:	Chief Compliance Officer
Date:	02/09/2026

FAQ

What ownership stake in Amicus Therapeutics (FOLD) does William Blair report?

William Blair Investment Management reports beneficial ownership of 10,627,717 Amicus Therapeutics common shares, representing 3.4% of the class as of 12/31/2025. This stake is reported on an amended Schedule 13G filing.

Does William Blair have voting power over its Amicus Therapeutics (FOLD) shares?

Yes. William Blair reports sole voting power over 10,321,526 Amicus Therapeutics shares and no shared voting power. It also has sole dispositive power over 10,627,717 shares, according to the Schedule 13G/A filing.

Is William Blair’s Amicus Therapeutics (FOLD) stake above the 5% threshold?

No. William Blair reports beneficial ownership of 3.4% of Amicus Therapeutics common stock. The filing’s Item 5 confirms ownership of 5 percent or less of the class, which is below the typical 5% large-holder reporting threshold.

Why did William Blair file an amended Schedule 13G for Amicus Therapeutics (FOLD)?

The document is labeled Amendment No. 1 to a Schedule 13G, reflecting updated beneficial ownership information as of 12/31/2025. It restates William Blair’s share count, percentage ownership, and voting and dispositive powers in Amicus Therapeutics.

Is William Blair seeking control of Amicus Therapeutics (FOLD) through this stake?

No. William Blair certifies the securities were acquired and are held in the ordinary course of business and not for the purpose of changing or influencing control of Amicus Therapeutics, consistent with a passive investment under Schedule 13G rules.

What type of reporting person is William Blair in the Amicus Therapeutics (FOLD) filing?

William Blair Investment Management, LLC is organized in Delaware and files as an entity eligible under Schedule 13G categories, including as an investment adviser under applicable SEC rules, as indicated in the classification section of the ownership report.