Deep Track entities disclose 3.01% stake in Definium Therapeutics (DFTX)

Rhea-AI Filing Summary

Definium Therapeutics, Inc. is the subject of a Schedule 13G/A reporting that Deep Track Capital, LP; Deep Track Biotechnology Master Fund, Ltd.; and David Kroin beneficially own 3,000,000 common shares, representing 3.01% of the class as of March 31, 2026. The filing states the outstanding share base used for the calculation was 99,698,129 common shares as of February 19, 2026, cited from the issuer's Form 10-K. The filing is a joint statement signed by David Kroin on behalf of the reporting persons and clarifies that Deep Track Capital, LP is the relevant entity for which Kroin may be considered a control person.

Insights

Governance Specialist

Minor passive stake disclosed by Deep Track entities and an individual director.

The filing lists a 3.01% beneficial ownership position represented as 3,000,000 shares with shared voting and dispositive power. The position is reported on a Schedule 13G/A, which is consistent with passive investment reporting standards when ownership is below typical control thresholds.

Timing and disclosures to note: the ownership amount is stated as of March 31, 2026 while the outstanding base is sourced from a February 19, 2026 figure in the issuer's 10-K. Subsequent amendments or sales by the holders would require new filings.

Investor Relations Advisor

This is an informational disclosure about a sub-5% passive holding; it does not signal immediate corporate action.

The joint filing emphasizes shared voting and dispositive power of 3,000,000 shares and includes a joint filing statement under Rule 13d-1(k). It identifies Deep Track Capital, LP as the primary entity for control-person characterization.

For stakeholders, the relevant items are the 3.01% stake and the cited outstanding share count of 99,698,129; these anchor the ownership percentage calculation used in public records.

Key Figures

Shares beneficially owned: 3,000,000 shares Percent of class: 3.01% Shares outstanding used: 99,698,129 shares

3 metrics

Shares beneficially owned 3,000,000 shares Amount owned by reporting persons as of March 31, 2026

Percent of class 3.01% Ownership percentage calculated using outstanding shares noted in filing

Shares outstanding used 99,698,129 shares Outstanding common stock as of February 19, 2026 per issuer's Form 10-K

Key Terms

Schedule 13G/A, beneficially own, joint filing statement

3 terms

Schedule 13G/A regulatory

"reporting on ownership of 3,000,000 common shares"

A Schedule 13G/A is an amended public filing with the U.S. securities regulator that updates a previous Schedule 13G, disclosing when an individual or group holds a substantial (typically over 5%) stake in a company and is claiming a passive, non‑controlling intent. Investors monitor these updates because rising or falling holdings can signal changing confidence, potential future moves, or shifts in voting power — like watching a public ledger where large shareholders quietly adjust their positions.

beneficially own financial

"Amount beneficially owned: 3,000,000"

Beneficially own means having the economic rights and risks of a security—such as the right to receive dividends, sell the shares, or profit from price changes—whether or not your name appears on the official share register. Think of it like renting a car: you use it and reap the benefits even if the title lists someone else. Investors care because beneficial ownership determines who truly controls value, must be disclosed under securities rules, and can signal potential influence or trading activity that affects a stock’s price.

joint filing statement regulatory

"JOINT FILING STATEMENT PURSUANT TO RULE 13d-1(k)"

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 4)

Definium Therapeutics, Inc.

(Name of Issuer)

Common Shares

(Title of Class of Securities)

24477V105

(CUSIP Number)

03/31/2026

(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): 24477V105

1

Names of Reporting Persons

Deep Track Capital, 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

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 3,000,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 3,000,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

3,000,000.00

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)

3.01 %

12

Type of Reporting Person (See Instructions)

IA, OO

SCHEDULE 13G

CUSIP Number(s): 24477V105

1

Names of Reporting Persons

Deep Track Biotechnology Master Fund, Ltd.

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

CAYMAN ISLANDS

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 3,000,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 3,000,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

3,000,000.00

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)

3.01 %

12

Type of Reporting Person (See Instructions)

CO

SCHEDULE 13G

CUSIP Number(s): 24477V105

1

Names of Reporting Persons

David Kroin

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 3,000,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 3,000,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

3,000,000.00

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)

3.01 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Definium Therapeutics, Inc.
(b)	Address of issuer's principal executive offices: One World Trade Center, Suite 8500, New York, NY 10007
Item 2.
(a)	Name of person filing: (i) Deep Track Capital, LP (ii) Deep Track Biotechnology Master Fund, Ltd. (iii) David Kroin
(b)	Address or principal business office or, if none, residence: (i) 200 Greenwich Ave, 3rd Floor, Greenwich, CT 06830 (ii) c/o Walkers Corporate Limited, 190 Elgin Ave, George Town, KY1-9001, Cayman Islands (iii) c/o Deep Track Capital, LP, 200 Greenwich Ave, 3rd Floor, Greenwich, CT 06830
(c)	Citizenship: (i) Delaware (ii) Cayman Islands (iii) United States
(d)	Title of class of securities: Common Shares
(e)	CUSIP No.: 24477V105
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: 3,000,000
(b)	Percent of class: 3.01%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 0
	(ii) Shared power to vote or to direct the vote: 3,000,000
	(iii) Sole power to dispose or to direct the disposition of: 0
	(iv) Shared power to dispose or to direct the disposition of: 3,000,000
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.
	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. Deep Track Capital, LP is the relevant entity for which David Kroin may be considered a control person.
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 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.

Deep Track Capital, LP

Signature:	/s/ David Kroin
Name/Title:	David Kroin, Managing Member of the General Partner of the Investment Adviser
Date:	05/15/2026

Deep Track Biotechnology Master Fund, Ltd.

Signature:	/s/ David Kroin
Name/Title:	David Kroin, Director
Date:	05/15/2026

David Kroin

Signature:	/s/ David Kroin
Name/Title:	David Kroin
Date:	05/15/2026

Exhibit Information

Item 4: Information with respect to the Reporting Persons' ownership of the Common Stock as of March 31, 2026, is incorporated by reference to items (5) - (9) and (11) of the cover page of the respective Reporting Person. The amount beneficially owned by each Reporting Person is determined using 99,698,129 Common Stock outstanding as of February 19, 2026, according to the issuer's 10-K filed with the SEC on February 26, 2026 JOINT FILING STATEMENT PURSUANT TO RULE 13d-1(k) The undersigned acknowledge and agree that the foregoing statement on SCHEDULE 13G, is filed on behalf of each of the undersigned and that all subsequent amendments to this statement on SCHEDULE 13G, shall be filed on behalf of each of the undersigned without the necessity of filing additional joint acquisition statements. The undersigned acknowledge that each shall be responsible for the timely filing of such amendments, and for the completeness and accuracy of the information concerning him or it contained therein, but shall not be responsible for the completeness and accuracy of the information concerning the others, except to the extent that he or it knows or has reason to believe that such information is inaccurate. Dated: May 15, 2026 Deep Track Capital, LP By: /s/ David Kroin David Kroin, Managing Member of the General Partner of the Investment Adviser Deep Track Biotechnology Master Fund, Ltd. By: /s/ David Kroin David Kroin, Director David Kroin By: /s/ David Kroin David Kroin

FAQ

What stake does Deep Track Capital report in Definium Therapeutics (DFTX)?

Deep Track reports beneficial ownership of 3,000,000 common shares, equal to 3.01% of the class as of March 31, 2026. The percentage uses an outstanding share count of 99,698,129 from the issuer's Form 10-K dated February 19, 2026.

Who filed the Schedule 13G/A for DFTX and who signed it?

The Schedule 13G/A was filed jointly by Deep Track Capital, LP, Deep Track Biotechnology Master Fund, Ltd., and David Kroin. It is signed by David Kroin in multiple capacities on behalf of the reporting persons, dated May 15, 2026.

Does the filing indicate passive or active intent for the DFTX stake?

The use of Schedule 13G/A and the filing language indicates a passive reporting posture rather than an active takeover intent. The filing does not state plans to acquire control or change company management.

What voting and disposition powers are reported for the 3,000,000 DFTX shares?

The filing shows 0 shares with sole voting or dispositive power and 3,000,000 shares with shared voting and shared dispositive power, as disclosed under Item 4 of the Schedule 13G/A.

How was the 3.01% ownership percentage calculated for DFTX?

The percentage is based on 3,000,000 shares divided by the stated outstanding common shares of 99,698,129 as of February 19, 2026, a figure cited from Definium Therapeutics' Form 10-K filed February 26, 2026.