United Microelectronics (NYSE: UMC) VP lists over 2.0M shares held

Rhea-AI Filing Summary

UNITED MICROELECTRONICS CORP vice president HSU SHIH-CHIEH filed an initial Form 3 reporting existing holdings in the company’s common shares. The filing shows 2,075,080 common shares held directly and an additional 2,889 common shares held indirectly through a spouse.

The direct position includes 928,800 shares of Restricted Stock Award (RSA). A specified number of these RSA shares will vest each year on December 5 from 2026 through 2029, indicating a multi-year equity compensation schedule. The filing records holdings only and does not reflect new purchases or sales.

Insider Trade Summary

2 transactions reported

Mixed 2 txns

Insider HSU SHIH-CHIEH

Role Vice President

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

Holdings After Transaction: Common Shares — 2,075,080 shares (Direct, null); Common Shares — 2,889 shares (Indirect, By Spouse)

Footnotes (1)

1. [object Object]

Key Figures

Direct common shares held: 2,075,080 shares Indirect common shares held by spouse: 2,889 shares Restricted Stock Award component: 928,800 shares +2 more

5 metrics

Direct common shares held 2,075,080 shares Total direct UMC common shares following reported holdings

Indirect common shares held by spouse 2,889 shares Indirect ownership classified as By Spouse

Restricted Stock Award component 928,800 shares Part of direct holdings designated as RSA

RSA vesting period start December 5, 2026 Annual vesting date for a portion of RSA shares

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

Key Terms

Restricted Stock Award (RSA), Form 3, indirect, beneficial ownership

4 terms

Restricted Stock Award (RSA) financial

"Includes 928,800 shares of Restricted Stock Award (RSA) and a specified number of shares"

Form 3 regulatory

"vice president HSU SHIH-CHIEH filed an initial Form 3 reporting existing holdings"

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.

indirect financial

"an additional 2,889 common shares held indirectly through a spouse"

beneficial ownership financial

"shares held indirectly through a spouse indicate indirect beneficial ownership attribution"

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.

Understanding Insider Trading Forms →

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

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1. Name and Address of Reporting Person^*

HSU SHIH-CHIEH

(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)
	Vice President

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	2,075,080(1)	D
Common Shares	2,889	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)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Includes 928,800 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)