UMC vice president reports 2.48M share holding

UNITED MICROELECTRONICS CORP vice president Chen Ming‑Tsung has filed an initial Form 3 reporting his equity stake in the company.

Rhea-AI Filing Summary

UNITED MICROELECTRONICS CORP vice president Chen Ming‑Tsung has filed an initial Form 3 reporting his equity stake in the company. The filing shows direct beneficial ownership of 2,484,660 Common Shares after the reported entry.

This total includes 674,600 shares granted as a Restricted Stock Award (RSA). According to the footnote, a specified number of these RSA shares will vest each year on December 5 from 2026 through 2029, meaning portions of this award become fully owned over that period.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider CHEN MING-TSUNG

Role Vice President

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

Holdings After Transaction: Common Shares — 2,484,660 shares (Direct)

Footnotes (1)

1. F1. Includes 674,600 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.

Key Figures

Total Common Shares held: 2,484,660 shares Restricted Stock Award shares: 674,600 shares RSA vesting schedule: Annually on December 5, 2026-2029

3 metrics

Total Common Shares held 2,484,660 shares Direct ownership reported on Form 3

Restricted Stock Award shares 674,600 shares Included within total Common Shares

RSA vesting schedule Annually on December 5, 2026-2029 Vesting timing for Restricted Stock Award

Key Terms

Form 3, Restricted Stock Award (RSA), vest

3 terms

Form 3 regulatory

"Vice President Chen Ming‑Tsung has filed an initial Form 3 reporting his equity stake"

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.

Restricted Stock Award (RSA) financial

"Includes 674,600 shares of Restricted Stock Award (RSA) and a specified number"

vest financial

"a specified number of shares subject to the RSA will vest annually on December 5"

A vest is the process by which an employee earns the right to receive certain benefits or ownership interests, such as stock or retirement funds, over time. It’s similar to earning a reward gradually, ensuring that the benefit becomes fully yours only after a set period or meeting specific conditions. This makes it important for investors because it determines when they can actually claim or use those benefits.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What does Chen Ming-Tsung’s Form 3 filing for UMC report?

The Form 3 shows that vice president Chen Ming-Tsung directly holds 2,484,660 Common Shares of UNITED MICROELECTRONICS CORP. This includes a substantial Restricted Stock Award component that vests in tranches between 2026 and 2029, reflecting long-term equity-based compensation.

How many UMC shares are included in Chen Ming-Tsung’s Restricted Stock Award?

The filing states that Chen Ming-Tsung’s holdings include 674,600 shares of Restricted Stock Award (RSA). These shares are part of his total reported 2,484,660 Common Shares and are subject to a vesting schedule over several future years.

When will Chen Ming-Tsung’s Restricted Stock Award in UMC vest?

The footnote explains that a specified number of Chen Ming-Tsung’s 674,600 RSA shares will vest annually on December 5 from 2026 to 2029. This schedule gradually converts restricted shares into fully vested shares over four consecutive years.

Does the UMC Form 3 show any recent share purchases or sales by Chen Ming-Tsung?

The Form 3 is an initial ownership report and lists Chen Ming-Tsung’s 2,484,660 Common Shares position, including restricted stock. The transaction data are categorized as a holding entry with an unknown code, and do not show explicit purchases or sales.

What type of security does Chen Ming-Tsung hold in UNITED MICROELECTRONICS CORP?

Chen Ming-Tsung’s reported position consists of Common Shares of UNITED MICROELECTRONICS CORP. Within this total, 674,600 shares are designated as a Restricted Stock Award (RSA), which vest in annual installments from 2026 through 2029.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Accepted by SEC EDGAR 05/07/2026 - 06:11 AM Learn about SEC filing dates

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

OMB Number:			3235-0104
Estimated average burden
hours per response:			0.5

1. Name and Address of Reporting Person^*

CHEN MING-TSUNG

(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	2,484,660(1)	D

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 674,600 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)