[Form 4] Zai Lab Limited American Insider Trading Activity

Rhea-AI Filing Summary

Chen Yajing, Chief Financial Officer of Zai Lab Ltd (ZLAB), reported changes in her beneficial ownership. On 08/14/2025 she had 1,250 restricted share units vest, converting to 1,250 American Depositary Shares (ADSs). On 08/15/2025 she sold 610 ADSs at $35.267 and 828 ADSs at $35.53; the 610-share sale was to cover taxes and the 828-share sale was executed under a Rule 10b5-1 trading plan adopted March 3, 2025.

After these transactions she beneficially owns 16,720 ADSs (each ADS = 10 ordinary shares). The filing was signed by an attorney-in-fact on 08/18/2025.

Insights

Financial Analyst

TL;DR: Insider vested 1,250 ADSs then sold 1,438 ADSs, leaving 16,720 ADSs; transactions include tax-covering sale and a 10b5-1 plan sale.

The transactions are routine compensation-related activity rather than a large, discretionary disposition. The vesting of RSUs increases vested holdings but the net reduction of 1,438 ADSs reflects sales to satisfy tax obligations and a pre-established 10b5-1 plan. The sizes (1,250 vested; 610 and 828 sold) are modest relative to typical institutional holdings and do not indicate an immediate material change to ownership control.

Corporate Governance Expert

TL;DR: Disclosure follows standard governance practices: RSU vesting disclosure and sales under a 10b5-1 plan with tax-withholding sale noted.

The filing properly reports vested RSUs, automatic tax-withholding sales, and a separate sale effected under a documented 10b5-1 trading plan. Timing and documentation reduce insider trading concerns. The remaining beneficial ownership of 16,720 ADSs is transparent; no unusual derivative activity or related-party transactions are disclosed.

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).

X

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^*

Chen Yajing

(Last) (First) (Middle)

C/O ZAI LAB LIMITED

314 MAIN STREET, 4TH FLOOR, SUITE 100

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Zai Lab Ltd [ ZLAB ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
08/14/2025

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

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 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
American Depositary Shares(1)	08/14/2025		M		1,250(2)	A	(3)	18,158	D
American Depositary Shares(1)	08/15/2025		S		610(4)	D	$35.267	17,548	D
American Depositary Shares(1)	08/15/2025		S(5)		828	D	$35.53	16,720	D

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
Restricted Share Units	(3)	08/14/2025		M			1,250	(6)	(6)	American Depositary Shares(1)	1,250	$0	2,500	D

Explanation of Responses:

1. Each American Depositary Share ("ADS") represents ten Ordinary Shares of the issuer. Our ADSs and Ordinary Shares are fully fungible. For purposes of this Form 4, we are reporting this in terms of ADSs.

2. ADSs acquired upon vesting of Restricted Share Units ("RSUs").

3. Each RSU represents a contingent right to receive one ADS.

4. These ADSs were sold automatically to cover taxes upon vesting of RSUs.

5. This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 3, 2025.

6. The RSUs vest in equal annual installments over four years beginning on 08/14/2024, the first anniversary of the date of grant. Vested shares will be delivered in the form of ADSs to the reporting person following vesting.

	/s/ Bruce Blefeld, Attorney-in-Fact	08/18/2025
	** 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.

FAQ

What did ZLAB CFO Chen Yajing report on Form 4?

Chen Yajing reported 1,250 RSUs vested on 08/14/2025 and sales of 610 ADSs at $35.267 and 828 ADSs at $35.53 on 08/15/2025.

How many ZLAB ADSs does Chen Yajing beneficially own after these transactions?

Following the reported transactions she beneficially owns 16,720 ADSs.

Why were some ADSs sold after vesting?

The filing states 610 ADSs were sold automatically to cover taxes and 828 ADSs were sold pursuant to a Rule 10b5-1 trading plan adopted March 3, 2025.

What does each ADS represent for Zai Lab (ZLAB)?

Each American Depositary Share (ADS) represents 10 ordinary shares of Zai Lab, and ADSs and ordinary shares are fully fungible per the filing.

When were the transactions and when was the form signed?

The RSU vesting occurred on 08/14/2025, the sales on 08/15/2025, and the Form 4 was signed by attorney-in-fact on 08/18/2025.