GC Corp (ARTV insider) adds 1.43M Artiva shares in open‑market buys

Rhea-AI Filing Summary

GC Corp. and subsidiary GC Cell Corporation, both 10% owners of Artiva Biotherapeutics, Inc., bought a combined 1,432,291 shares of Artiva common stock in open‑market transactions. The purchases were made on May 11, 2026 at $11.52 per share.

After these transactions, GC Cell Corporation held 1,607,734 Artiva shares indirectly and GC Corp. held 4,391,969 shares directly. Footnotes explain that GC Corp. is a Korean holding company ultimately controlled by its board, whose members may be deemed to share voting and investment power but each disclaims beneficial ownership except for any pecuniary interest.

Insights

Equity ownership analyst

Large 10% owner increases Artiva stake via open‑market purchases.

Entities affiliated with GC Corp., a 10% shareholder of Artiva Biotherapeutics, Inc., executed two open‑market purchases totaling 1,432,291 shares at $11.52 per share on May 11, 2026. These are straightforward common‑stock buys, not derivative exercises or grants.

Post‑transaction, GC Corp. directly owns 4,391,969 shares and its subsidiary GC Cell Corporation holds 1,607,734 shares indirectly. Footnotes clarify that GC Corp.’s board collectively controls these entities and that each director disclaims beneficial ownership beyond any pecuniary interest. No trading plan or hedging structure is mentioned in the excerpt.

Insider Trade Summary

Net Buyer: 1,432,291 shares ($16,499,992)

Net Buy 2 txns

Insider GC Corp., GC Cell Corp

Role null | null

Bought 1,432,291 shs ($16.50M)

Type	Security	Shares	Price	Value
Purchase	Common Stock	1,085,069	$11.52	$12.50M
Purchase	Common Stock	347,222	$11.52	$4.00M

Holdings After Transaction: Common Stock — 4,391,969 shares (Direct, null); Common Stock — 1,607,734 shares (Indirect, By GC Cell Corporation)

Footnotes (1)

1. GC Corp., a public Korean holdings company, is ultimately controlled by its board of directors. As of March 26, 2026, the board consists of: Mr. Yong-Jun Huh, Huh Il-Sup, Park Yong-Tae, Kang Joonho, and Lee Choonwoo. Each of these individual directors of GC Corp. may be deemed to share voting and investment power over the shares held by GC Corp. and each disclaims beneficial ownership of all shares held by GC Corp., except to the extent of any pecuniary interest therein. The shares are held directly by GC Cell Corporation. GC Corp., a public Korean holdings company, is the parent company of GC Cell Corporation and is ultimately controlled by its board of directors. As of March 26, 2026, the board consists of: Mr. Yong-Jun Huh, Huh Il-Sup, Park Yong-Tae, Kang Joonho, and Lee Choonwoo. Each of these individual directors of GC Corp. may be deemed to share voting and investment power over the shares held by GC Corp. and GC Cell Corporation and each disclaims beneficial ownership of all shares held by such entities, except to the extent of any pecuniary interest therein.

Key Figures

Total shares bought: 1,432,291 shares Purchase price: $11.52 per share Indirect purchase size: 347,222 shares +3 more

6 metrics

Total shares bought 1,432,291 shares Net open-market purchases on May 11, 2026

Purchase price $11.52 per share Price for both reported common stock transactions

Indirect purchase size 347,222 shares Common stock held indirectly by GC Cell Corporation after purchase

Direct purchase size 1,085,069 shares Common stock bought directly by GC Corp.

Direct holdings after trade 4,391,969 shares Artiva common stock held directly by GC Corp. post‑transaction

Indirect holdings after trade 1,607,734 shares Artiva common stock held indirectly via GC Cell Corporation

Key Terms

open-market purchase, ten percent owner, indirect ownership, beneficial ownership, +1 more

5 terms

open-market purchase financial

"transaction_action: open-market purchase"

An open-market purchase is when an investor or a company buys shares on a public stock exchange at the going market price, rather than through a private deal. It matters to investors because these purchases change how many shares are available, can push the stock price up or signal confidence from large buyers, and often affect per-share metrics like earnings—think of it like someone buying lots of apples off a grocery shelf, reducing supply and potentially raising the price.

ten percent owner financial

"GC Corp. and GC Cell Corp are each a ten percent owner"

indirect ownership financial

"ownership_type: indirect; nature_of_ownership: By GC Cell Corporation"

beneficial ownership financial

"each disclaims beneficial ownership of all shares held by GC Corp."

Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.

voting and investment power financial

"may be deemed to share voting and investment power over the shares"

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

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
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

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

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

GC Corp.

(Last) (First) (Middle)

107 IHYEON-RO,30BEON-GIL

GILHEUNG-GU

(Street)

YONGIN-SI GYEONGGI-DO 16924

(City) (State) (Zip)

KOREA, REPUBLIC OF

(Country)

2. Issuer Name and Ticker or Trading Symbol
Artiva Biotherapeutics, Inc. [ ARTV ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/11/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

	Form filed by One Reporting Person
X	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	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
Common Stock	05/11/2026		P		1,085,069	A	$11.52	4,391,969	D(1)
Common Stock	05/11/2026		P		347,222	A	$11.52	1,607,734	I	By GC Cell Corporation(2)

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 (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	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 (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (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: 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

1. Name and Address of Reporting Person^*

GC Corp.

(Last) (First) (Middle)

107 IHYEON-RO,30BEON-GIL

GILHEUNG-GU

(Street)

YONGIN-SI GYEONGGI-DO 16924

(City) (State) (Zip)

KOREA, REPUBLIC OF

(Country)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

GC Cell Corp

(Last) (First) (Middle)

107 IHYEON-RO, 30BEON-GI

GIHEUNG-GU,

(Street)

YONGIN-SI GYEONGGI-DO 16924

(City) (State) (Zip)

KOREA, REPUBLIC OF

(Country)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

Explanation of Responses:

1. GC Corp., a public Korean holdings company, is ultimately controlled by its board of directors. As of March 26, 2026, the board consists of: Mr. Yong-Jun Huh, Huh Il-Sup, Park Yong-Tae, Kang Joonho, and Lee Choonwoo. Each of these individual directors of GC Corp. may be deemed to share voting and investment power over the shares held by GC Corp. and each disclaims beneficial ownership of all shares held by GC Corp., except to the extent of any pecuniary interest therein.

2. The shares are held directly by GC Cell Corporation. GC Corp., a public Korean holdings company, is the parent company of GC Cell Corporation and is ultimately controlled by its board of directors. As of March 26, 2026, the board consists of: Mr. Yong-Jun Huh, Huh Il-Sup, Park Yong-Tae, Kang Joonho, and Lee Choonwoo. Each of these individual directors of GC Corp. may be deemed to share voting and investment power over the shares held by GC Corp. and GC Cell Corporation and each disclaims beneficial ownership of all shares held by such entities, except to the extent of any pecuniary interest therein.

	GC Corp. By: /s/ Yong-Jun Huh, Chief Executive Officer	05/28/2026
	GC Cell Corporation By: /s/ Jaiwang Kim, Chief Executive Officer	05/28/2026
	** Signature of Reporting Person	Date
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.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transactions did GC Corp. report in Artiva Biotherapeutics (ARTV)?

GC Corp. and its subsidiary GC Cell Corporation reported buying 1,432,291 shares of Artiva common stock in open‑market transactions on May 11, 2026, at $11.52 per share, increasing both their direct and indirect ownership positions in the company.

How many Artiva (ARTV) shares did GC Corp. hold after these purchases?

After the May 11, 2026 transactions, GC Corp. directly held 4,391,969 shares of Artiva common stock. Its subsidiary GC Cell Corporation held an additional 1,607,734 shares indirectly, according to the reported post‑transaction ownership figures in the filing data.

What was the purchase price in GC Corp.’s Form 4 for Artiva (ARTV)?

Both reported transactions were open‑market purchases of Artiva common stock at $11.52 per share. One purchase covered 347,222 shares held indirectly via GC Cell Corporation, and the other covered 1,085,069 shares held directly by GC Corp. as a ten percent owner.

Who controls the Artiva (ARTV) shares held by GC Corp. and GC Cell Corporation?

The filing states GC Corp., a public Korean holding company, is ultimately controlled by its board of directors. Those directors may be deemed to share voting and investment power over shares held by GC Corp. and GC Cell Corporation but each disclaims beneficial ownership except for any pecuniary interest.

Were GC Corp.’s Artiva (ARTV) transactions open‑market buys or another type?

The transactions are coded as “P,” described as purchases in open market or private transactions. The normalized data further classifies them as open‑market purchases of Artiva common stock, rather than option exercises, grants, gifts, or tax‑withholding dispositions.