Sec Form 3 Filing - SIM Boon @ Artius II Acquisition Inc. - 2025-02-12

FORM 3 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number: 3235-0287 Expires: November 30, 2011 Estimated average burden hours per response... 0.5

1. Name and Address of Reporting Person SIM Boon 2. Issuer Name and Ticker or Trading Symbol Artius II Acquisition Inc. [ AACB] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director X __ 10% Owner X __ Officer (give title below) _____ Other (specify below) CEO, CFO (Last) (First) (Middle) 3 COLUMBUS CIRCLE, 15TH FLOOR 3. Date of Earliest Transaction (MM/DD/YY) 02/12/2025 (Street) NEW YORK, NY10019 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Ordinary Shares 175,000 ( 1 ) I ( 7 ) By Artius II Acquisition Partners LLC

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Class B Ordinary Shares ( 2 ) ( 2 ) ( 2 ) Class A Ordinary Shares 5,750,000 ( 3 ) ( 4 ) ( 5 ) I ( 7 ) By Artius II Acquisition Partners LLC Rights ( 6 ) ( 6 ) ( 6 ) Class A Ordinary Shares 17,500 ( 6 ) I ( 7 ) By Artius II Acquisition Partners LLC

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other SIM Boon 3 COLUMBUS CIRCLE, 15TH FLOOR NEW YORK, NY10019 X X CEO, CFO Signatures /s/ Sophie Low, as attorney-in-fact for Boon Sim 02/12/2025 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Includes 175,000 Class A ordinary shares underlying the private placement units ("Private Placement Units"), which were acquired by the Reporting Person in a private placement taking place simultaneously with the issuer's initial business combination. Each Private Placement Unit consists of one Class A ordinary share and one right entitling the holder thereof to receive one tenth (1/10) of one Class A ordinary share. ( 2 )As described in the issuer's registration statement on Form S-1 (File No. 333-283020) (the "Registration Statement") under the heading "Description of Securities-Founder Shares," the Class B ordinary shares, par value $0.0001 per share, of the issuer will automatically convert into Class A ordinary shares, par value $0.0001 per share, of the issuer at the time of the issuer's initial business combination, or earlier at the option of the holder, on a one-for-one basis, subject to certain adjustment, and have no expiration date. ( 3 )5,750,000 represents the number of Class B ordinary shares beneficially owned by the Reporting Person as of the filing date of this Form 3. The Class B ordinary shares convert into Class A ordinary shares at a ratio such that the number of Class A ordinary shares issuable upon conversion of the Class B ordinary shares will equal, in the aggregate, on an as-converted basis, 20% of the sum of (i) the total number of all Class A ordinary shares outstanding upon the completion of the issuer's initial public offering (including any Class A ordinary shares issued pursuant to the underwriter's over-allotment option and excluding the shares underlying the Private Placement Units), plus (ii) all Class A ordinary shares and equity-linked securities issued or deemed issued, in connection with the closing of the issuer's (continues in footnote no. 4) ( 4 )initial business combination (excluding any shares or equity-linked securities issued, or to be issued, to any seller in the issuer's initial business combination and any private placement-equivalent shares issued to the Reporting Person or any of its affiliates or to the issuer's officers or directors upon conversion of working capital loans); provided, that the distributable shares, as defined in the Registration Statement, and the Reporting Person's forfeiture of a number of Class B ordinary shares equal to the number of distributable shares will be disregarded for purposes of this adjustment. ( 5 )The Class B ordinary shares include (i) up to 750,000 shares that are subject to forfeiture in the event the underwriters of the issuer's initial public offering do not exercise in full their over-allotment option and (ii) 1,000,000 (or 1,150,000 if the underwriter's over-allotment option is exercised in full) shares that are subject to forfeiture concurrently with the distribution of distributable shares, in each case as described in the Registration Statement. ( 6 )Representing 17,500 Class A ordinary shares underlying the Private Placement Units. As of the date of this filing, the Reporting Person beneficially owns 175,000 rights. Each right is automatically exchangeable for one tenth (1/10) of one Class A ordinary share upon the completion of the issuer's initial business combination. ( 7 )Artius II Acquisition Partners LLC, the issuer's sponsor, is the record holder of the shares reported herein. The Reporting Person is the sole member of Aecus II Partners LLC, which is the managing partner of Artius II Acquisition Partners LLC and exercises voting and investment power with respect to the Class B ordinary shares and the Class A ordinary shares underlying the private placement units in each case held by Artius Acquisition Partners LLC. The shares beneficially owned by Artius II Acquisition Partners LLC may also be deemed to be beneficially owned by the Reporting Person.

Remarks: Exhibit List: Exhibit 24 Power of Attorney

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.