SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549


SCHEDULE 13G


UNDER THE SECURITIES EXCHANGE ACT OF 1934
Onconetix, Inc.
(Name of Issuer)


Common stock, par value $0.00001 per share
(Title of Class of Securities)


68237Q401
(CUSIP Numbers)


07/20/2026
(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)




SCHEDULE 13G
CUSIP Number(s):
68237Q401


1 Names of Reporting Persons

Keystone Capital Partners, LLC
2 Check the appropriate box if a member of a Group (see instructions)

☐  (a)
☐  (b)
3SEC 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: 223,717.00
7 Sole Dispositive Power: 0.00
8 Shared Dispositive Power: 223,717.00
9 Aggregate Amount Beneficially Owned by Each Reporting Person

223,717.00
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)

6.1 %
12 Type of Reporting Person (See Instructions)

OO

Comment for Type of Reporting Person: The percentages used herein are calculated based upon 3,691,492 shares of common stock outstanding as of June 5, 2026, as reported by the Company in its Prospectus dated June 16, 2026 (Registration No. 333-296615), filed with the SEC on June 17, 2026. Amount beneficially owned excludes (i) 1,214,228 shares issuable upon exercise of warrants held by Keystone, (ii) 12,195 shares issuable upon conversion of shares of preferred stock held by Keystone, based on an alternate conversion price of $0.82, and (iii) 99,742,303 shares issuable pursuant to a common stock purchase agreement by and between the Company and Keystone, which in each case are subject to a prohibition on issuance if such issuance would result in the holder beneficially owning over 4.99% of the common stock.


SCHEDULE 13G
CUSIP Number(s):
68237Q401


1 Names of Reporting Persons

RANZ Group LLC
2 Check the appropriate box if a member of a Group (see instructions)

☐  (a)
☐  (b)
3SEC 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: 223,717.00
7 Sole Dispositive Power: 0.00
8 Shared Dispositive Power: 223,717.00
9 Aggregate Amount Beneficially Owned by Each Reporting Person

223,717.00
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)

6.1 %
12 Type of Reporting Person (See Instructions)

OO

Comment for Type of Reporting Person: The percentages used herein are calculated based upon 3,691,492 shares of common stock outstanding as of June 5, 2026, as reported by the Company in its Prospectus dated June 16, 2026 (Registration No. 333-296615), filed with the SEC on June 17, 2026. Amount beneficially owned excludes (i) 1,214,228 shares issuable upon exercise of warrants held by Keystone, (ii) 12,195 shares issuable upon conversion of shares of preferred stock held by Keystone, at an alternate conversion price of $0.82, and (iii) 99,742,303 shares issuable pursuant to a common stock purchase agreement by and between the Company and Keystone, which in each case are subject to a prohibition on issuance if such issuance would result in the holder beneficially owning over 4.99% of the common stock.


SCHEDULE 13G
CUSIP Number(s):
68237Q401


1 Names of Reporting Persons

Fredric Zaino
2 Check the appropriate box if a member of a Group (see instructions)

☐  (a)
☐  (b)
3SEC 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: 223,717.00
7 Sole Dispositive Power: 0.00
8 Shared Dispositive Power: 223,717.00
9 Aggregate Amount Beneficially Owned by Each Reporting Person

223,717.00
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)

6.1 %
12 Type of Reporting Person (See Instructions)

OO

Comment for Type of Reporting Person: The percentages used herein are calculated based upon 3,691,492 shares of common stock outstanding as of June 5, 2026, as reported by the Company in its Prospectus dated June 16, 2026 (Registration No. 333-296615), filed with the SEC on June 17, 2026. Amount beneficially owned excludes (i) 1,214,228 shares issuable upon exercise of warrants held by Keystone, (ii) 12,195 shares issuable upon conversion of shares of preferred stock held by Keystone, at an alternate conversion price of $0.82, and (iii) 99,742,303 shares issuable pursuant to a common stock purchase agreement by and between the Company and Keystone, which in each case are subject to a prohibition on issuance if such issuance would result in the holder beneficially owning over 4.99% of the common stock.



SCHEDULE 13G

Item 1. 
(a) Name of issuer:

Onconetix, Inc.
(b) Address of issuer's principal executive offices:

201 E. Fifth Street, Suite 1900, Cincinnati, Ohio 45202
Item 2. 
(a) Name of person filing:

This statement is filed on behalf of the following persons with respect to shares of common stock of the Company acquired by them (the "Shares"): (i) Keystone Capital Partners, LLC, Delaware limited liability company ("Keystone"), with respect to Shares beneficially owned by it; (ii) RANZ Group LLC, a Delaware limited liability company ("RANZ Group"), with respect to Shares beneficially owned by it; and (iii) Fredric Zaino, an individual ("Mr. Zaino"), with respect to Shares beneficially owned by him. The foregoing persons are hereinafter referred to collectively as the "Reporting Persons." Any disclosures herein with respect to persons other than the Reporting Persons are made on information and belief after making inquiry to the appropriate party. RANZ Group and Mr. Zaino do not own any Shares directly. Keystone is managed by RANZ Group. RANZ Group maintains investment and voting power with respect to the securities held or controlled by Keystone. Fredric Zaino, an individual, controls RANZ Group. By reason of the provisions of Rule 13d-3 of the Securities Exchange Act of 1934, as amended, RANZ Group and Mr. Zaino may be deemed to own beneficially all of the Shares (constituting approximately 6.1% of the shares outstanding). Each of RANZ Group and Mr. Zaino disclaim beneficial ownership of any of the securities covered by this statement, except to the extent of any pecuniary interest therein.
(b) Address or principal business office or, if none, residence:

139 Fulton Street, Suite 412, New York, NY 10038
(c) Citizenship:

Keystone is a Delaware limited liability company. RANZ Group is a Delaware limited liability company. Mr. Zaino is a United States citizen.
(d) Title of class of securities:

Common stock, par value $0.00001 per share
(e) CUSIP No.:

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:

Keystone: 223,717 RANZ Group: 223,717 Mr. Zaino: 223,717
(b) Percent of class:

Keystone: 6.1% RANZ Group: 6.1% Mr. Zaino: 6.1%
(c) Number of shares as to which the person has:
  (i) Sole power to vote or to direct the vote:

Keystone: 0 RANZ Group: 0 Mr. Zaino: 0

  (ii) Shared power to vote or to direct the vote:

Keystone: 223,717 RANZ Group: 223,717 Mr. Zaino: 223,717

  (iii) Sole power to dispose or to direct the disposition of:

Keystone: 0 RANZ Group: 0 Mr. Zaino: 0

  (iv) Shared power to dispose or to direct the disposition of:

Keystone: 223,717 RANZ Group: 223,717 Mr. Zaino: 223,717

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.
 
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 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.

 
Keystone Capital Partners, LLC
 Signature:/s/ Fredric Zaino
 Name/Title:Fredric Zaino, as Managing Member of Keystone Capital Partners, LLC, as the CIO of Keystone Capital Partners, LLC
 Date:07/27/2026
 
RANZ Group LLC
 Signature:/s/ Fredric Zaino
 Name/Title:Fredric Zaino, as Managing Member of RANZ Group LLC
 Date:07/27/2026
 
Fredric Zaino
 Signature:/s/ Fredric Zaino
 Name/Title:Fredric Zaino, individually
 Date:07/27/2026
Exhibit Information: Exhibit 99.1 Joint Filing Agreement

Exhibit 99.1

 

JOINT FILING AGREEMENT

 

The undersigned hereby agree that statements on Schedules 13G and/or 13D and Forms 3, 4 and 5 with respect to the securities of Onconetix, Inc. and any amendments thereto signed by each of the undersigned shall be filed on behalf of each of the undersigned pursuant to and in accordance with the provisions of Rule 13d-1(k) promulgated under the Securities Exchange Act of 1934, as amended. The undersigned hereby further agree that this Joint Filing Agreement may be included as an exhibit to such statements or amendments. This Joint Filing Agreement may be executed in any number of counterparts, all of which taken together shall constitute one and the same instrument.

 

Dated: July 27, 2026

 

  Keystone Capital Partners, LLC
     
  By: RANZ Group LLC,
    Its Manager
     
  By: /s/ Fredric Zaino  
    Name: Fredric Zaino
    Title: Managing Member

 

  RANZ Group LLC
     
  By: /s/ Fredric Zaino
    Name: Fredric Zaino
    Title: Managing Member

 

  Fredric Zaino
     
  By: /s/ Fredric Zaino