UNITED MICROELECTRONICS CORP (UMC) CISO reports 3.7M-share insider stake

Filing Impact

(Neutral)

Filing Sentiment

(Neutral)

Form Type

Rhea-AI Filing Summary

UNITED MICROELECTRONICS CORP executive Wu Chung-Hsien has filed an initial ownership report showing substantial common share holdings. The filing lists 3,685,584 common shares held directly and 304 shares held indirectly through a spouse. A footnote states that 1,127,500 of these shares are a Restricted Stock Award that will vest in specified amounts each year on December 5 from 2026 to 2029, indicating a multi‑year equity compensation schedule tied to continued service.

Insider Trade Summary

2 transactions reported

Mixed 2 txns

Insider WU CHUNG-HSIEN

Role CISO & SVP

Type	Security	Shares	Price	Value
holding	Common Shares	--	--	--
holding	Common Shares	--	--	--

Holdings After Transaction: Common Shares — 3,685,584 shares (Direct, null); Common Shares — 304 shares (Indirect, By Spouse)

Footnotes (1)

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Key Figures

Direct common share holdings: 3,685,584 shares Indirect common share holdings: 304 shares Restricted Stock Award: 1,127,500 shares +2 more

5 metrics

Direct common share holdings 3,685,584 shares Total common shares held directly by Wu Chung-Hsien

Indirect common share holdings 304 shares Common shares held indirectly by spouse

Restricted Stock Award 1,127,500 shares Portion of holdings designated as RSA

RSA vesting period start December 5, 2026 First annual vesting date for RSA shares

RSA vesting period end December 5, 2029 Final annual vesting date for RSA shares

Key Terms

Restricted Stock Award (RSA), indirect, Form 3

3 terms

Restricted Stock Award (RSA) financial

"Includes 1,127,500 shares of Restricted Stock Award (RSA) and a specified number of shares subject to the RSA will vest annually"

indirect financial

"total_shares_following_transaction": "304.0000" ... "ownership_type": "indirect""

Form 3 regulatory

"INSIDER FILING DATA (Form 3): { "issuerName": "UNITED MICROELECTRONICS CORP""

Form 3 is the initial public filing that officers, directors and large shareholders must submit to report their ownership of a company’s securities when they become insiders. It acts like an opening inventory sheet that gives investors a starting point to see who holds significant stakes and to spot later trades or potential conflicts of interest, helping assess insider confidence and transparency.

Understanding Insider Trading Forms →

05/07/2026 - 06:03 AM

SEC 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

OMB APPROVAL

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1. Name and Address of Reporting Person^*

WU CHUNG-HSIEN

(Last)

(First)

(Middle)

8F, NO.68, SEC. 1, NEIHU RD.,

(Street)

TAIPEI

TAIWAN

11493

(City)

(State)

(Zip)

TAIWAN

(Country)

2. Date of Event Requiring Statement (Month/Day/Year)
04/29/2026

3. Issuer Name and Ticker or Trading Symbol
UNITED MICROELECTRONICS CORP [ UMC ]

3a. Foreign Trading Symbol
[2303.TW]

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

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

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

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

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

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)
Common Shares	3,685,584⁽¹⁾	D
Common Shares	304	I	By Spouse

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: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
1. Title of Derivative Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)

Explanation of Responses:

1. Includes 1,127,500 shares of Restricted Stock Award (RSA) and a specified number of shares subject to the RSA will vest annually on December 5 from 2026 to 2029.

Remarks:

Exhibit List Exhibit 24: Power of Attorney

	/s/Chitung Liu, attorney-in-fact	05/07/2026
	** 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 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).
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 3: SEC 1473 (03-26)

Source: View Original Filing on SEC EDGAR

FAQ

What does the Form 3 for UNITED MICROELECTRONICS CORP (UMC) show about Wu Chung-Hsien's holdings?

The Form 3 shows that Wu Chung-Hsien beneficially owns common shares in UNITED MICROELECTRONICS CORP, including a large direct position and a small indirect position via a spouse. This filing establishes Wu’s baseline equity stake as a CISO & SVP at the company.

How many UNITED MICROELECTRONICS CORP (UMC) shares does Wu Chung-Hsien hold directly and indirectly?

Wu Chung-Hsien holds 3,685,584 UNITED MICROELECTRONICS CORP common shares directly and 304 shares indirectly through a spouse. These figures together reflect the total common share ownership reported in this initial Form 3 insider filing for the executive.

What portion of Wu Chung-Hsien's UNITED MICROELECTRONICS CORP (UMC) shares are Restricted Stock Awards?

The filing notes that 1,127,500 of Wu Chung-Hsien’s UNITED MICROELECTRONICS CORP common shares are a Restricted Stock Award. This RSA represents a significant part of the reported holdings and reflects equity compensation that vests over several future years.

When will Wu Chung-Hsien's Restricted Stock Awards in UNITED MICROELECTRONICS CORP (UMC) vest?

The Restricted Stock Award shares for Wu Chung-Hsien are scheduled to vest annually on December 5 from 2026 to 2029. Each year during this period, a specified number of RSA shares will vest, aligning compensation with ongoing service at UNITED MICROELECTRONICS CORP.

Does the UNITED MICROELECTRONICS CORP (UMC) Form 3 show any insider buying or selling by Wu Chung-Hsien?

The Form 3 functions as an initial ownership statement and lists Wu Chung-Hsien’s existing common share holdings. It does not report new open‑market purchases or sales, but instead discloses current direct, indirect, and restricted stock award positions as of the reported date.