[SCHEDULE 13G/A] Spero Therapeutics, Inc. SEC Filing

Rhea-AI Filing Summary

Anson-managed entities reported beneficial ownership of 1,615,469 shares of Spero Therapeutics common stock, representing 2.9% of the 55,910,641 shares outstanding. The holdings are disclosed on a Schedule 13G/A dated for the event 06/30/2025 and signed on 08/14/2025 by representatives of Anson Funds Management LP, Anson Management GP LLC, Anson Advisors Inc., Tony Moore, Amin Nathoo and Moez Kassam.

The filing states the shares are held by the Fund and that the position is held in the ordinary course of business and not to influence control of the issuer. Voting and dispositive power over the 1,615,469 shares is shown as shared (no sole power reported). The filing cites the issuer's outstanding share count from the issuer's May 13, 2025 quarterly report.

Insights

Investment Analyst

TL;DR: Anson group disclosed a passive 2.9% stake in SPRO, a non-controlling position that is unlikely to force near-term corporate changes.

The Schedule 13G/A reports 1,615,469 shares (2.9% of 55,910,641 shares). The filing classifies the position as held in the ordinary course of business and not intended to influence control, consistent with passive investor reporting thresholds. Shared voting and dispositive power is indicated across the Anson entities. For investors, this is a transparent ownership disclosure rather than an activist move; it signals interest but not control.

Corporate Governance Expert

TL;DR: The disclosure documents beneficial ownership and shared authority but shows no group formation or control intent, so governance impact appears limited.

The filing lists multiple affiliated filers and confirms shared voting/dispositive power over 1,615,469 shares (2.9%). Item 10 certification states the stake was not acquired to change control. No members of a group, no greater-than-5% ownership, and no solicitation or group formation are reported. From a governance perspective, this is routine transparency with no immediate governance implications disclosed.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 2)

SPERO THERAPEUTICS, INC.

(Name of Issuer)

Common Stock, par value $0.001 per share

(Title of Class of Securities)

84833T103

(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. 84833T103

1

Names of Reporting Persons

Anson Funds Management LP

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

TEXAS

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 1,615,469.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,615,469.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

1,615,469.00

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)

2.9 %

12

Type of Reporting Person (See Instructions)

IA, PN

SCHEDULE 13G

CUSIP No. 84833T103

1

Names of Reporting Persons

Anson Management GP 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

TEXAS

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 1,615,469.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,615,469.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

1,615,469.00

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)

2.9 %

12

Type of Reporting Person (See Instructions)

HC, OO

SCHEDULE 13G

CUSIP No. 84833T103

1

Names of Reporting Persons

Tony Moore

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 0.00
6	Shared Voting Power 1,615,469.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,615,469.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

1,615,469.00

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)

2.9 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

CUSIP No. 84833T103

1

Names of Reporting Persons

Anson Advisors Inc.

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

CANADA (FEDERAL LEVEL)

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 1,615,469.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,615,469.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

1,615,469.00

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)

2.9 %

12

Type of Reporting Person (See Instructions)

FI, CO

SCHEDULE 13G

CUSIP No. 84833T103

1

Names of Reporting Persons

Amin Nathoo

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

CANADA (FEDERAL LEVEL)

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 1,615,469.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,615,469.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

1,615,469.00

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)

2.9 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

CUSIP No. 84833T103

1

Names of Reporting Persons

Moez Kassam

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

CANADA (FEDERAL LEVEL)

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 1,615,469.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 1,615,469.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

1,615,469.00

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)

2.9 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

Item 1.
(a)	Name of issuer: SPERO THERAPEUTICS, INC.
(b)	Address of issuer's principal executive offices: 675 Massachusetts, Avenue, 14th FloorCambridge, MA, 02139
Item 2.
(a)	Name of person filing: Anson Funds Management LP, Anson Management GP LLC, Mr. Tony Moore, Anson Advisors Inc., Mr. Amin Nathoo and Mr. Moez Kassam
(b)	Address or principal business office or, if none, residence: For Anson Funds Management LP, Anson Management GP LLC and Mr. Moore: 16000 Dallas Parkway, Suite 800 Dallas, Texas 75248 For Anson Advisors Inc., Mr. Nathoo and Mr. Kassam: 181 Bay Street, Suite 4200 Toronto, ON M5J 2T3
(c)	Citizenship: Anson Funds Management LP is a limited partnership organized under the laws of the State of Texas. Anson Management GP LLC is a limited liability company organized under the laws of the State of Texas. Mr. Moore is a United States citizen. Anson Advisors Inc. is a corporation organized under the laws of Ontario, Canada. Mr. Nathoo and Mr. Kassam are each Canadian citizens.
(d)	Title of class of securities: Common Stock, par value $0.001 per share
(e)	CUSIP No.: 84833T103
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).
	Canadian Investment Advisor
Item 4.	Ownership
(a)	Amount beneficially owned: Anson Funds Management LP, Anson Management GP LLC, Mr. Moore, Anson Advisors Inc., Mr. Nathoo and Mr. Kassam are the beneficial owners of 1,615,469 shares of Common Stock held by the Fund.
(b)	Percent of class: Anson Funds Management LP, Anson Management GP LLC, Mr. Moore, Anson Advisors Inc., Mr. Nathoo and Mr. Kassam are the beneficial owners of 2.9% of the outstanding shares of Common Stock. This percentage is determined by dividing 1,615,469 by 55,910,641, which is number of Common Stock issued and outstanding, as reported in the Issuer's Quarterly Report on form 10-Q filed with the Securities and Exchange Commission (the "SEC") on May 13, 2025.
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: See Section 4(a)
	(ii) Shared power to vote or to direct the vote: See Section 4(a)
	(iii) Sole power to dispose or to direct the disposition of: See Section 4(a)
	(iv) Shared power to dispose or to direct the disposition of: See Section 4(a)
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. By signing below I certify that, to the best of my knowledge and belief, the foreign regulatory scheme applicable to Anson Advisors Inc. is substantially comparable to the regulatory scheme applicable to the functionally equivalent U.S. institution(s). I also undertake to furnish to the Commission staff, upon request, information that would otherwise be disclosed in a Schedule 13D.

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.

Anson Funds Management LP

Signature:	/s/ Tony Moore
Name/Title:	Tony Moore, Manager
Date:	08/14/2025

Anson Management GP LLC

Signature:	/s/ Tony Moore
Name/Title:	Tony Moore, Manager
Date:	08/14/2025

Tony Moore

Signature:	/s/ Tony Moore
Name/Title:	Tony Moore, Manager
Date:	08/14/2025

Anson Advisors Inc.

Signature:	/s/ Amin Nathoo
Name/Title:	Amin Nathoo, Director
Date:	08/14/2025

Signature:	/s/ Moez Kassam
Name/Title:	Moez Kassam, Director
Date:	08/14/2025

Amin Nathoo

Signature:	/s/ Amin Nathoo
Name/Title:	Amin Nathoo, Director
Date:	08/14/2025

Moez Kassam

Signature:	/s/ Moez Kassam
Name/Title:	Moez Kassam, Director
Date:	08/14/2025

FAQ

What stake does Anson report in SPRO?

Anson reports beneficial ownership of 1,615,469 shares, equal to 2.9% of SPRO's 55,910,641 outstanding shares.

Does the filing indicate Anson intends to influence control of Spero (SPRO)?

No. The filing certifies the shares were acquired and are held in the ordinary course of business and not to change or influence control of the issuer.

Who signed the Schedule 13G/A for Anson?

Signatures include Tony Moore for Anson Funds Management LP and Anson Management GP LLC, and Amin Nathoo and Moez Kassam for Anson Advisors Inc.; all dated 08/14/2025.

What type of reporting persons are listed?

Reporting persons include investment adviser and private fund entities and individuals, classified as IA, PN, HC, OO, FI, CO, IN depending on the filer.

What voting and dispositive powers are reported?

The filing reports 0 sole voting/dispositive power and 1,615,469 shared voting and dispositive power for each reporting person.