[SCHEDULE 13G] Fulcrum Therapeutics, Inc. Passive Investment Disclosure (>5%)
Therapeutics, Inc. holder reports 8.22% stake
Nantahala Capital Management, LLC, together with Wilmot B. Harkey and Daniel Mack, reports beneficial ownership of common stock of Therapeutics, Inc. (par value $0.001 per share, CUSIP 359616109).
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Nantahala Capital Management, LLC, together with Wilmot B. Harkey and Daniel Mack, reports beneficial ownership of common stock of Therapeutics, Inc. (par value $0.001 per share, CUSIP 359616109).
As of June 30, 2026, the reporting persons may be deemed beneficial owners of 5,475,040 shares, representing 8.22% of the outstanding common stock. These shares are held by funds and separately managed accounts under Nantahala’s control. Each reporting person has shared voting power and shared dispositive power over 5,475,040 shares and no sole voting or dispositive power. Harkey and Mack file as control persons with respect to shares beneficially owned by Nantahala, an investment adviser.
Key Figures
Shares beneficially owned:5,475,040 sharesPercent of class:8.22%Shared voting power:5,475,040 shares+3 more
6 metrics
Shares beneficially owned5,475,040 sharesCommon stock beneficially owned as of June 30, 2026
Percent of class8.22%Percentage of Therapeutics, Inc. common stock as of June 30, 2026
Shared voting power5,475,040 sharesShares over which each reporting person has shared voting power
Shared dispositive power5,475,040 sharesShares over which each reporting person has shared dispositive power
CUSIP359616109CUSIP number for Therapeutics, Inc. common stock
Par value$0.001 per sharePar value of Therapeutics, Inc. common stock
"Nantahala may be deemed to be the beneficial owner of 5,475,040 Shares"
A beneficial owner is the person who ultimately owns or controls a financial asset or property, even if their name isn't directly on official documents. Think of it like someone who secretly holds the keys to a safe deposit box—others may appear to have access, but the true owner is the one who benefits from what's inside. Identifying beneficial owners helps ensure transparency and prevent illegal activities like money laundering or fraud.
shared voting powerfinancial
"Shared Voting Power 5,475,040.00"
Shared voting power occurs when two or more parties jointly have the right to vote or decide how a block of company shares is cast, like co-owners who must agree before moving a piece of furniture. Investors care because who controls voting rights affects board elections, major corporate decisions and takeover outcomes, and shared control can alter regulatory disclosures and the practical influence any holder has over a company’s direction and value.
shared dispositive powerfinancial
"Shared Dispositive Power 5,475,040.00"
Schedule 13Gregulatory
"Each of Messrs. Harkey and Mack is filing this as a control person"
A Schedule 13G is a formal document that investors file with the government when they acquire a large ownership stake in a company, usually for investment purposes rather than control. It helps keep the public informed about who owns significant parts of a company's shares, which can influence how the company is managed and how investors make decisions. Filing this schedule is important for transparency and understanding the ownership landscape of publicly traded companies.
control personfinancial
"each of Messrs. Harkey and Mack is filing this as a control person"
A control person is an individual or entity that can significantly influence a company’s decisions and direction through ownership, voting power, or contractual rights—think of them as the captain who can steer the ship. Investors care because a control person’s choices affect corporate strategy, board appointments, and transactions that can raise or lower a stock’s value, and they often carry additional legal responsibilities and disclosure requirements to protect other shareholders.
FAQ
AI-generated questions and answers. How Rhea-AI works. Not financial advice.
What percentage of FULC common stock does Nantahala Capital Management report owning?
Nantahala Capital Management and its principals report beneficial ownership of 8.22% of Therapeutics, Inc. common stock. This percentage is based on 5,475,040 shares beneficially owned as of June 30, 2026, relative to the company’s outstanding shares.
How many FULC shares are beneficially owned by Nantahala and its principals?
Nantahala and its principals report beneficial ownership of 5,475,040 shares of Therapeutics, Inc. common stock. These shares are held by funds and separately managed accounts under Nantahala’s control as of June 30, 2026.
What type of SEC filing is this Schedule 13G for FULC?
This is a Schedule 13G filing reporting passive beneficial ownership in Therapeutics, Inc. common stock. It discloses the holdings and voting/dispositive powers of Nantahala Capital Management and its principals as of June 30, 2026.
What voting and dispositive powers do the FULC reporting persons have over their shares?
Each reporting person has 0 shares with sole voting or dispositive power and 5,475,040 shares with shared voting and shared dispositive power. This reflects coordinated control over the same block of Therapeutics, Inc. common stock.
Who are the reporting persons in the FULC Schedule 13G filing?
The reporting persons are Nantahala Capital Management, LLC, Wilmot B. Harkey, and Daniel Mack. Harkey and Mack are managing members of Nantahala and file as control persons regarding the shares beneficially owned by Nantahala.
As of what date are the FULC beneficial ownership figures reported?
All ownership figures are reported as of June 30, 2026. On that date, the reporting persons may be deemed to beneficially own 5,475,040 shares, representing 8.22% of Therapeutics, Inc. common stock, with shared voting and dispositive power.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
FULCRUM THERAPEUTICS, INC.
(Name of Issuer)
Common stock, par value $0.001 per share
(Title of Class of Securities)
359616109
(CUSIP Number)
06/30/2026
(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)
schemaVersion:
SCHEDULE 13G
CUSIP Number(s):
359616109
1
Names of Reporting Persons
Nantahala Capital 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
MASSACHUSETTS
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
5,475,040.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
5,475,040.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,475,040.00
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)
8.22 %
12
Type of Reporting Person (See Instructions)
IA
SCHEDULE 13G
CUSIP Number(s):
359616109
1
Names of Reporting Persons
Wilmot B. Harkey
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
5,475,040.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
5,475,040.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,475,040.00
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)
8.22 %
12
Type of Reporting Person (See Instructions)
HC
SCHEDULE 13G
CUSIP Number(s):
359616109
1
Names of Reporting Persons
Daniel Mack
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
5,475,040.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
5,475,040.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,475,040.00
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)
8.22 %
12
Type of Reporting Person (See Instructions)
HC
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
FULCRUM THERAPEUTICS, INC.
(b)
Address of issuer's principal executive offices:
26 LANDSDOWNE STREET CAMBRIDGE, MASSACHUSETTS, 02139
Item 2.
(a)
Name of person filing:
(1) Nantahala Capital Management, LLC ("Nantahala")
(2) Wilmot B. Harkey
(3) Daniel Mack (together the "Reporting Persons")
(b)
Address or principal business office or, if none, residence:
130 Main St. 2nd Floor, New Canaan, Connecticut 06840
(c)
Citizenship:
(1) Nantahala is a Massachusetts limited liability company.
(2) Each of Messrs. Harkey and Mack is a citizen of the United States of America.
(d)
Title of class of securities:
Common stock, par value $0.001 per share
(e)
CUSIP Number(s):
359616109
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:
As of June 30, 2026, Nantahala may be deemed to be the beneficial owner of 5,475,040 Shares held by funds and separately managed accounts under its control, and as the managing members of Nantahala, each of Messrs. Harkey and Mack may be deemed to be a beneficial owner of those Shares.
(b)
Percent of class:
As of June 30, 2026, each of the Reporting Persons may be deemed to be the beneficial owner of the following percentage of the total number of Shares outstanding:
(1) Nantahala Capital Management, LLC ("Nantahala") : 8.22%
(2) Wilmot B. Harkey: 8.22%
(3) Daniel Mack: 8.22%
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
(1) Nantahala Capital Management, LLC ("Nantahala") : 0 Shares.
(2) Wilmot B. Harkey: 0 Shares.
(3) Daniel Mack: 0 Shares.
(ii) Shared power to vote or to direct the vote:
(1) Nantahala Capital Management, LLC ("Nantahala") : 5,475,040 Shares.
(2) Wilmot B. Harkey: 5,475,040 Shares.
(3) Daniel Mack: 5,475,040 Shares.
(iii) Sole power to dispose or to direct the disposition of:
(1) Nantahala Capital Management, LLC ("Nantahala") : 0 Shares.
(2) Wilmot B. Harkey: 0 Shares.
(3) Daniel Mack: 0 Shares.
(iv) Shared power to dispose or to direct the disposition of:
(1) Nantahala Capital Management, LLC ("Nantahala") : 5,475,040 Shares.
(2) Wilmot B. Harkey: 5,475,040 Shares.
(3) Daniel Mack: 5,475,040 Shares.
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.
If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary.
Each of Messrs. Harkey and Mack is filing this Schedule 13G as a control person in respect of shares beneficially owned by Nantahala, an investment adviser as described in ss. 240.13d-1(b)(1)(ii)(E). See Item 4(a).
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.
