Major Spyre Therapeutics (SYRE) holder sells 4.68M shares and updates 9.99% stake

Rhea-AI Filing Summary

Spyre Therapeutics’ major shareholder Fairmount Funds and related individuals updated their ownership disclosures in this Schedule 13D amendment. Fairmount’s Fund II converted 16,667 shares of Series B Preferred Stock into 666,680 common shares for no cash consideration under the preferred stock terms.

On June 23, 2026, Fund II sold 4,684,781 common shares in a block trade at $85.31 per share. After these changes and applying a 9.99% beneficial ownership cap, the reporting group’s position includes 8,581,440 shares issuable from Series A Preferred Stock plus 228,646 option shares, representing up to about 10% of Spyre’s common stock.

The filing also notes that director Peter Harwin resigned from Spyre’s board on May 27, 2026, and states his resignation was not due to any disagreement with the company on its operations, policies, or practices.

Insights

Equity ownership and governance analyst

Large holder trims stake via block sale but remains near 10% with board change.

Fairmount’s Fund II converted preferred shares into 666,680 common shares at no cash cost, then executed a sizable block sale of 4,684,781 shares at $85.31 per share. This reshapes its mix of preferred and common exposure while keeping a meaningful position.

Post-transaction, the reporting group’s interest, capped by a 9.99% beneficial ownership limit, still represents millions of shares when combining Series A Preferred Stock and options. A cap like this limits further conversions that would push ownership above that threshold.

The resignation of director Peter Harwin on May 27, 2026, expressly described as not due to disagreements, removes a representative of this large investor from the board. Subsequent company filings may provide more color on governance dynamics and any future changes in Fairmount’s ownership.

Key Figures

Block trade size: 4,684,781 shares Block trade price: $85.31 per share Series B conversion: 666,680 shares +5 more

8 metrics

Block trade size 4,684,781 shares Common stock sold by Fund II on June 23, 2026

Block trade price $85.31 per share Sale price for 4,684,781 common shares

Series B conversion 666,680 shares Common shares from conversion of 16,667 Series B Preferred Stock

Series A conversion capacity 8,581,440 shares Common shares issuable from 214,536 Series A Preferred within 9.99% cap

Options held by reporting persons 228,646 shares Common shares underlying options exercisable within 60 days

Beneficial ownership percentage 9.99% Harwin and Kiselak beneficial ownership of common stock

Shares outstanding base (Fairmount/Fund II) 96,572,019 shares Common stock outstanding as of June 23, 2026 for certain calculations

Shares outstanding base (Harwin/Kiselak) 96,769,096 shares Common stock outstanding as of June 23, 2026 for their calculations

Key Terms

Schedule 13D, beneficial ownership limitation, Series A Preferred Stock, Series B Non-Voting Convertible Preferred Stock, +2 more

6 terms

Schedule 13D regulatory

"This Amendment No. 7 amends and supplements the statement on originally filed with the Securities and Exchange Commission"

A Schedule 13D is a legal document that investors file with regulators when they buy a large enough stake in a company to potentially influence its management or decisions. It provides details about the investor’s intention, ownership stake, and plans, helping other investors understand who is gaining control and what their motives might be.

beneficial ownership limitation financial

"in excess of the beneficial ownership limitation of 9.99%"

A beneficial ownership limitation is a rule that caps the percentage of a company’s shares an investor can be treated as owning or controlling for voting, regulatory or tax purposes. It matters to investors because it can restrict how many shares a person or group can buy or vote, affect takeover chances, and influence share liquidity and value — like a speed limit that prevents any single driver from taking over the whole road.

Series A Preferred Stock financial

"shares of Series A Preferred Stock, par value $0.0001 per share"

Series A preferred stock is a type of ownership share in a company that gives investors certain advantages, such as priority in receiving profits or getting their money back if the company is sold or goes bankrupt. It is often issued during early funding stages to attract investors by offering more security than common shares. This stock matters to investors because it provides a safer way to invest while still holding potential for future gains.

Series B Non-Voting Convertible Preferred Stock financial

"Certificate of Designation of Preferences, Rights and Limitations of Series B Non-Voting Convertible Preferred Stock"

A Series B non-voting convertible preferred stock is a class of company shares that gives holders financial priority—such as fixed dividends and first claim on assets if the company is sold—while not granting voting rights. It can be converted into regular common shares under set conditions, which matters to investors because conversion can increase upside participation but also dilute existing owners; the preference reduces downside risk like a safety buffer.

block trade financial

"On June 23, 2026, Fund II sold in a block trade a total of 4,684,781 shares"

A block trade is a large, privately arranged sale or purchase of a company's shares or bonds between big investors, often negotiated to avoid upsetting the public market price. Think of it like selling a truckload of goods directly to one buyer instead of unloading it on a busy street — it moves a lot of supply at once and can signal shifting demand, affect immediate liquidity, and influence short-term stock prices.

Certificate of Designation regulatory

"pursuant to Section 6.2 of the Certificate of Designation of Preferences, Rights and Limitations"

A certificate of designation is a formal document that spells out the specific rights and rules attached to a particular class or series of stock, usually preferred shares. Think of it as a rulebook or menu that lists dividend terms, liquidation priority, conversion or redemption rights and any special voting protections; investors use it to judge how much income, control or downside protection those shares will provide compared with other securities.

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

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Available on EDGAR 06/23/2026 - 09:45 PM Accepted by SEC EDGAR 06/23/2026 - 09:45 PM Learn about SEC filing dates

FAQ

How much Spyre Therapeutics (SYRE) stock did Fairmount’s Fund II sell in this filing?

Fund II sold 4,684,781 shares of Spyre Therapeutics common stock in a single block trade. The shares were sold on June 23, 2026 at a price of $85.31 per share, representing a substantial secondary-market transaction by a large shareholder.

What preferred shares were converted into Spyre Therapeutics (SYRE) common stock?

Fund II converted 16,667 shares of Series B Non-Voting Convertible Preferred Stock into 666,680 shares of Spyre Therapeutics common stock. The conversion followed the Certificate of Designation terms and was effected for no cash consideration, simply exchanging preferred equity for common shares.

What is the reporting group’s beneficial ownership percentage of Spyre Therapeutics (SYRE)?

The filing shows beneficial ownership percentages up to 9.99% of Spyre common stock for certain reporting persons. This percentage reflects shares issuable from Series A Preferred Stock and options, calculated using share counts and a 9.99% beneficial ownership limitation in the preferred terms.

What is the 9.99% beneficial ownership limitation mentioned for Spyre Therapeutics (SYRE)?

The 9.99% beneficial ownership limitation restricts how many Spyre common shares can be acquired through preferred stock conversion. Shares that would push a holder above 9.99% beneficial ownership are excluded, limiting additional conversions even if more preferred shares remain outstanding for that investor.

Did a Spyre Therapeutics (SYRE) director resign in connection with this Schedule 13D/A?

Yes. The filing states that director Peter Harwin resigned from the Spyre Therapeutics board on May 27, 2026. It explicitly notes that his resignation was not due to any disagreement with the company regarding operations, policies, or practices, indicating an orderly departure.

How many Spyre Therapeutics (SYRE) shares are tied to Fairmount’s Series A Preferred Stock and options?

The reporting group’s securities include 8,581,440 Spyre common shares issuable from 214,536 Series A Preferred shares, plus 228,646 common shares underlying options. These figures are calculated while applying the 9.99% beneficial ownership cap across the reporting persons’ combined holdings.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 7)

SPYRE THERAPEUTICS, INC.

(Name of Issuer)

Common Stock, $0.0001 par value

(Title of Class of Securities)

00773J202

(CUSIP Number)

Ms. Erin O'Connor
Fairmount Funds Management LLC, 200 Barr Harbor Drive, Suite 400
West Conshohocken, PA, 19428
(267) 262-5300

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

06/23/2026

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

schemaVersion:

SCHEDULE 13D

CUSIP Number(s): 00773J202

1

Name of reporting person

Fairmount Funds Management LLC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 8,835,440.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 8,835,440.00

11

Aggregate amount beneficially owned by each reporting person

8,835,440.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

9.15 %

14

Type of Reporting Person (See Instructions)

IA

Comment for Type of Reporting Person:

The securities represent 8,835,440 shares of common stock, $0.0001 par value per share (the "Common Stock") issuable upon conversion of 220,886 shares of Series A Preferred Stock, par value $0.0001 per share (the "Series A Preferred Stock"), held directly by Fairmount Healthcare Fund II L.P. ("Fund II"). The securities exclude shares of Common Stock issuable upon conversion of shares of Series A Preferred Stock held directly by Fund II in excess of the beneficial ownership limitation of 9.99%. Row 13 is based on 96,572,019 shares of Common Stock outstanding as of June 23, 2026, consisting of (i) 86,841,253 shares of Common Stock outstanding as of April 28, 2026, as reported in the Company's Form 10-Q filed on May 5, 2026, (ii) 666,680 shares of Common Stock issued upon the June 23, 2026 conversion by Fund II of 16,667 shares of the Series B Preferred Stock, par value $0.0001 per share (the "Series B Preferred Stock") (iii) 228,646 shares underlying options that are currently exercisable or will be exercisable within 60 days of the date of this filing by the Reporting Persons and (iv) 8,835,440 shares of Common Stock underlying the 220,886 shares of Series A Preferred Stock owned by Fund II, applying the beneficial ownership limitation.

SCHEDULE 13D

CUSIP Number(s): 00773J202

1

Name of reporting person

Fairmount Healthcare Fund II L.P.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 8,835,440.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 8,835,440.00

11

Aggregate amount beneficially owned by each reporting person

8,835,440.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

9.15 %

14

Type of Reporting Person (See Instructions)

PN

Comment for Type of Reporting Person:

The securities represent 8,835,440 shares of Common Stock issuable upon conversion of 220,886 shares of Series A Preferred Stock held directly by Fund II. The securities exclude shares of Common Stock issuable upon conversion of shares of Series A Preferred Stock held directly by Fund II in excess of the beneficial ownership limitation of 9.99%. Row 13 is based on 96,572,019 shares of Common Stock outstanding as of June 23, 2026, consisting of (i) 86,841,253 shares of Common Stock outstanding as of April 28, 2026, as reported in the Company's Form 10-Q filed on May 5, 2026, (ii) 666,680 shares of Common Stock issued upon the June 23, 2026 conversion by Fund II of 16,667 shares of the Series B Preferred Stock (iii) 228,646 shares underlying options that are currently exercisable or will be exercisable within 60 days of the date of this filing by the Reporting Persons and (iv) 8,835,440 shares of Common Stock underlying the 220,886 shares of Series A Preferred Stock owned by Fund II, applying the beneficial ownership limitation.

SCHEDULE 13D

CUSIP Number(s): 00773J202

1

Name of reporting person

Peter Evan Harwin

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 520,361.00
8	Shared Voting Power 9,146,840.00
9	Sole Dispositive Power 520,361.00
10	Shared Dispositive Power 9,146,840.00

11

Aggregate amount beneficially owned by each reporting person

9,667,201.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

9.99 %

14

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person:

The securities include (a) 406,038 shares of Common Stock held directly by Mr. Harwin, (b) 114,323 shares of Common Stock issuable upon the exercise of options that are currently exercisable or will be exercisable within 60 days of the date of this filing held directly by Mr. Harwin*, and (c) Fund II's direct holdings of 9,146,840 shares of Common Stock issuable upon conversion of 228,671 shares of Series A Preferred Stock held directly by Fund II. The securities exclude shares of Common Stock issuable upon conversion of shares of Series A Preferred Stock held directly by Fund II in excess of the beneficial ownership limitation of 9.99%. Row 13 is based on 96,769,096 shares of Common Stock outstanding as of June 23, 2026, consisting of (i) 86,841,253 shares of Common Stock outstanding as of April 28, 2026, as reported in the Company's Form 10-Q filed on May 5, 2026, (ii) 666,680 shares of Common Stock issued upon the June 23, 2026 conversion by Fund II of 16,667 shares of the Series B Preferred Stock, (iii) 114,323 shares of Common Stock underlying options that are currently exercisable or will be exercisable within 60 days of the date of this filing by Mr. Harwin and (iii) 9,146,840 shares of Common Stock underlying the 228,671 shares of Series A Preferred Stock owned by Fund II, applying the beneficial ownership limitation. * Under Mr. Harwin's arrangement with Fairmount, Mr. Harwin holds the options for one or more investment vehicles managed by Fairmount (each, a "Fairmount Fund"). Mr. Harwin is obligated to turn over to Fairmount any net cash or stock received from the option for the benefit of such Fairmount Fund. Mr. Harwin therefore disclaims beneficial ownership of the option and underlying common stock.

SCHEDULE 13D

CUSIP Number(s): 00773J202

1

Name of reporting person

Tomas Kiselak

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

SLOVAKIA

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 520,361.00
8	Shared Voting Power 9,146,840.00
9	Sole Dispositive Power 520,361.00
10	Shared Dispositive Power 9,146,840.00

11

Aggregate amount beneficially owned by each reporting person

9,667,201.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

9.99 %

14

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person:

The securities include (a) 406,038 shares of Common Stock held directly by Mr. Kiselak, (b) 114,323 shares of Common Stock issuable upon the exercise of options that are currently exercisable or will be exercisable within 60 days of the date of this filing held directly by Mr. Kiselak*, and (c) Fund II's direct holdings of 9,146,840 shares of Common Stock issuable upon conversion of 228,671 shares of Series A Preferred Stock held directly by Fund II. The securities exclude shares of Common Stock issuable upon conversion of shares of Series A Preferred Stock held directly by Fund II in excess of the beneficial ownership limitation of 9.99%. Row 13 is based on 96,769,096 shares of Common Stock outstanding as of June 23, 2026, consisting of (i) 86,841,253 shares of Common Stock outstanding as of April 28, 2026, as reported in the Company's Form 10-Q filed on May 5, 2026, (ii) 666,680 shares of Common Stock issued upon the June 23, 2026 conversion by Fund II of 16,667 shares of the Series B Preferred Stock, (iii) 114,323 shares of Common Stock underlying options that are currently exercisable or will be exercisable within 60 days of the date of this filing by Mr. Harwin and (iii) 9,146,840 shares of Common Stock underlying the 228,671 shares of Series A Preferred Stock owned by Fund II, applying the beneficial ownership limitation. * Under Mr. Kiselak's arrangement with Fairmount, Mr. Kiselak holds the options for one or more investment vehicles managed by Fairmount (each, a "Fairmount Fund"). Mr. Kiselak is obligated to turn over to Fairmount any net cash or stock received from the option for the benefit of such Fairmount Fund. Mr. Kiselak therefore disclaims beneficial ownership of the option and underlying common stock.

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Common Stock, $0.0001 par value
(b)	Name of Issuer: SPYRE THERAPEUTICS, INC.
(c)	Address of Issuer's Principal Executive Offices: 221 Crescent Street, Building 23, Suite 105, Waltham, MASSACHUSETTS , 02453.
Item 1 Comment: This Amendment No. 7 amends and supplements the statement on Schedule 13D originally filed with the Securities and Exchange Commission (the "SEC") on June 30, 2023, Amendment No. 1 filed on November 29, 2023, Amendment No. 2 filed on December 11, 2023, Amendment No. 3 filed on December 29, 2023, Amendment No. 4 filed on April 25, 2024, Amendment No. 5 filed on October 17, 2025, and Amendment No. 6 filed on April 20, 2026 (as amended, the "Statement" or the "Schedule 13D") by the Reporting Persons with respect to the Common Stock of the Company. Unless otherwise defined herein, capitalized terms used in this Amendment No. 7 shall have the meanings ascribed to them in the Statement. Unless amended or supplemented below, the information in the Statement remains unchanged.
Item 3.	Source and Amount of Funds or Other Consideration
	Item 3 of the Schedule 13D is hereby amended and supplemented as follows: On June 23, 2026, Fund II delivered to the Company a notice of conversion pursuant to Section 6.2 of the Certificate of Designation of Preferences, Rights and Limitations of Series B Non-Voting Convertible Preferred Stock (the "Certificate of Designation") to convert 16,667 shares of Series B Preferred Stock into 666,680 shares of Common Stock, in accordance with the terms of the Certificate of Designation. The conversion was effected for no cash consideration pursuant to the Certificate of Designation.
Item 4.	Purpose of Transaction
	Item 4 of the Schedule 13D is hereby amended and supplemented as follows: Resignation of Peter Harwin On May 27, 2026, Peter Harwin resigned from the Board of Directors of the Company. Mr. Harwin's resignation was not the result of any disagreement with the Company on any matter relating to the Company's operations, policies or practices.
Item 5.	Interest in Securities of the Issuer
(a)	The information in rows 11 and 13 of each of the cover pages (including the explanatory note in the "Comments") of this Amendment No. 7 is incorporated by reference herein. Together, the Reporting Persons' securities include (i) 8,581,440 shares of Common Stock issuable upon conversion of 214,536 shares of Series A Preferred Stock subject to the 9.99% beneficial ownership limitation applied to all of the securities owned by the Reporting Persons and (ii) 228,646 shares of Common Stock issuable upon the exercise of options held by the Reporting Persons that are currently exercisable or will be exercisable within 60 days of the date of this filing. The securities exclude 5,260,360 shares of Common Stock issuable upon conversion of 131,509 shares of Series A Preferred Stock held directly by Fund II in excess of the beneficial ownership limitation of 9.99%.
(b)	The information in rows 7 through 10 of each of the cover pages of this Amendment No. 7 is incorporated by reference herein.
(c)	Item 5(c) of the Schedule 13D is hereby supplemented as follows: On June 23, 2026, Fund II sold in a block trade a total of 4,684,781 shares of Common Stock at a price of $85.31 per share.
Item 7.	Material to be Filed as Exhibits.
	99.1 Joint Filing Agreement 99.1 (incorporated by reference to Exhibit 99.1 of the Reporting Persons' Schedule 13D filed with the SEC on October 17, 2025).

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.

Fairmount Funds Management LLC

Signature:	/s/ Peter Harwin
Name/Title:	Peter Harwin, Managing Member
Date:	06/23/2026

Signature:	/s/ Tomas Kiselak
Name/Title:	Tomas Kiselak, Managing Member
Date:	06/23/2026

Fairmount Healthcare Fund II L.P.

Signature:	/s/ Peter Harwin
Name/Title:	Peter Harwin, Managing Member
Date:	06/23/2026

Signature:	/s/ Tomas Kiselak
Name/Title:	Tomas Kiselak, Managing Member
Date:	06/23/2026

Peter Evan Harwin

Signature:	/s/ Peter Harwin
Name/Title:	Peter Harwin
Date:	06/23/2026

Tomas Kiselak

Signature:	/s/ Tomas Kiselak
Name/Title:	Tomas Kiselak
Date:	06/23/2026