UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): August 25, 2025

Eureka Acquisition Corp

(Exact name of registrant as specified in its charter)

Cayman Islands	001-42152	N/A
(State or other jurisdiction	(Commission File Number)	(IRS Employer
of incorporation)		Identification Number)

14 Prudential Tower

Singapore 049712

(Address of principal executive offices)

(+1) 949 899 1827

(Registrant’s telephone number, including area code)

Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐

Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

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Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐

Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

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Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act.

Title of each class	Trading Symbol	Name of each exchange on which registered
Units, consisting of one Class A ordinary share, $0.0001 par value, and one Right to acquire one-fifth of one Class A ordinary share	EURKU	The Nasdaq Stock Market LLC
Class A ordinary shares, par value $0.0001 per share	EURK	The Nasdaq Stock Market LLC
Rights, each whole right to acquire one-fifth of one Class A ordinary share	EURKR	The Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 1.01. Entry into a Material Definitive Agreement

The disclosures set forth under Item 2.03 are incorporated by reference.

Item 2.03 Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant

On August 25, 2025, Eureka Acquisition Corp, a Cayman Islands exempted company (the “Company”) issued an unsecured promissory note (the “Sponsor Note”) in the principal amount of up to $300,000 to Hercules Capital Management Corp, the sponsor of the Company (the “Sponsor”). The proceeds of the Sponsor Note, which may be drawn down from time to time until the Company consummates its initial business combination, will be used as general working capital purposes.

The Sponsor Note bears no interest and is payable in full upon the earlier to occur of (i) the consummation of the Company’s business combination or (ii) the date of expiry of the term of the Company (the “Maturity Date”). The following shall constitute an event of default: (i) a failure to pay the principal within five business days of the Maturity Date; (ii) the commencement of a voluntary or involuntary bankruptcy action, (iii) the breach of the Company’s obligations thereunder; (iv) any cross defaults; (v) an enforcement proceedings against the Company; and (vi) any unlawfulness and invalidity in connection with the performance of the obligations thereunder, in which case the Sponsor Note may be accelerated.

The payee of the Sponsor Note, the Sponsor, has the right, but not the obligation, to convert the Sponsor Note, in whole or in part, respectively, into private units (the “Units”) of the Company, each consisting of one Class A ordinary share, par value $0.0001 per share (the “Class A Ordinary Share”) and one right to receive one-fifth (1/5) of one Class A Ordinary Share upon the consummation of a business combination, as described in the prospectus of the Company (File No: 333-277780), by providing the Company with written notice of the intention to convert at least two business days prior to the closing of the business combination. The number of Units to be received by the Sponsor in connection with such conversion shall be an amount determined by dividing (x) the sum of the outstanding principal amount payable to the Sponsor by (y) $10.00.

The issuance of the Sponsor Note was made pursuant to the exemption from registration contained in Section 4(a)(2) of the Securities Act of 1933, as amended.

A copy of the Sponsor Note is attached as Exhibit 10.1 to this Current Report on Form 8-K and is incorporated herein by reference. The foregoing description of the Sponsor Note does not purport to be complete and is subject to, and is qualified in its entirety by, the full text of the Sponsor Note.

Item 3.02 Unregistered Sales of Equity Securities

The information disclosed under Item 2.03 of this Current Report on Form 8-K is incorporated by reference into this Item 3.02 to the extent required herein. The Units (and the underlying securities) issuable upon conversion of the Note, if any, (1) may not, subject to certain limited exceptions, be transferable or salable by the Sponsor until the completion of the Company’s initial business combination and (2) are entitled to registration rights.

Item 9.01 Financial Statements and Exhibits

Exhibit No.		Description of Exhibits
10.1		Sponsor Promissory Note dated August 25, 2025, issued by the Company to Hercules Capital Management Corp.
104		Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	Eureka Acquisition Corp

	By:	/s/ Fen Zhang
	Name:	Fen Zhang
	Title:	Chief Executive Officer

Date: August 26, 2025

Eureka Acquisition Corp 8-K