Initial Statement of Beneficial Ownership (Form 3)

FORM 3

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

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(Print or Type Responses)

1. Name and Address of Reporting Person * Katz Avi S 2. Date of Event Requiring Statement (Month/Day/Year) 10/03/2025 3. Issuer Name and Ticker or Trading Symbol GigCapital8 Corp. [GIW] (Last) (First) (Middle) C/O GIGCAPITAL8 CORP., 1731 EMBARCADERO ROAD, SUITE 200 4. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director __X__ 10% Owner __X__ Officer (give title below) _____ Other (specify below) Chief Executive Officer 5. If Amendment, Date Original Filed (Month/Day/Year) (Street) PALO ALTO, CA 94303 6. Individual or Joint/Group Filing (Check Applicable Line) ___ Form filed by One Reporting Person _X_ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Beneficially Owned

1.Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5) Class A ordinary shares 10,000(1)(2) I By GigAcquisitions8 Corp.(2)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.			SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Class B ordinary shares	(3)	(3)	Class A ordinary shares	6,053,167(4)	(3)	I	By GigAcquisitions8 Corp.(2)
Rights	(5)	(5)	Class A ordinary shares	2,000	(5)	I	By GigAcquisitions8 Corp.(2)

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Katz Avi S C/O GIGCAPITAL8 CORP. 1731 EMBARCADERO ROAD, SUITE 200 PALO ALTO, CA 94303	X	X	Chief Executive Officer
GigAcquisitions8 Corp. C/O GIGCAPITAL8 CORP. 1731 EMBARCADERO RD., SUITE 200 PALO ALTO, CA 94303		X
Dinu Raluca C/O GIGCAPITAL8 CORP. 1731 EMBARCADERO RD., SUITE 200 PALO ALTO, CA 94303	X

Signatures

/s/ Dr. Avi S. Katz, individually		10/07/2025
**Signature of Reporting Person		Date
/s/ Dr. Avi S. Katz, as managing member of GigAcquisitions8 Corp.		10/07/2025
**Signature of Reporting Person		Date
/s/ D. Raluca Dinu		10/07/2025
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 5(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).
(1)	Includes 10,000 Class A ordinary shares underlying the private placement units purchased concurrently with the initial public offering.
(2)	The Class B ordinary shares and Class A ordinary shares underlying the private placement units are held directly by GigAcquisitions8 Corp. (the "Sponsor"). The shares held by the Sponsor are beneficially owned equally (50% each) by Dr. Katz, the Issuer's Chief Executive Officer and Chairman of the Board of Directors, and Dr. Raluca Dinu, the Issuer's Director. Dr. Katz and Dr. Dinu are the members of the Sponsor, who both have the voting and dispositive power over the shares held by the Sponsor.
(3)	The Class B ordinary shares are convertible for the Issuer's Class A ordinary shares as described under the heading "Description of Securities" in the Issuer's Registration Statement on Form S-1 (File No. 333-289479) and have no expiration date.
(4)	Includes 6,053,167 Class B ordinary shares of the Issuer acquired by GigAcquisitions8 Corp. (the "Sponsor") prior to the Issuer's initial public offering convertible for the Issuer's Class A ordinary shares. As a result of the underwriter's full exercise of its over-allotment option to purchase 3,300,000 units on October 7, 2025, no such shares are subject to forfeiture.
(5)	Includes 10,000 rights underlying the private placement units, which were sold in a private placement taking place simultaneously with the Issuer's initial public offering. Each right is exchangeable for one-fifth of one Class A ordinary share upon the completion of the Issuer's initial business combination.

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