Zai Lab (ZLAB) CEO exercises options and sells 100,000 ADS under 10b5-1 plan

Rhea-AI Filing Summary

Zai Lab Ltd chairperson and CEO Du Ying reported option exercises and share sales under a pre-arranged trading plan. On March 6 and March 9, 2026, Du Ying exercised stock options for a total of 100,000 American Depositary Shares at an exercise price of $1.74 per ADS and then sold 100,000 ADS in open-market transactions at weighted average prices of $19.4187 and $19.0293 per ADS. Following these transactions, Du Ying directly holds 964,161 ADS. The filing notes that each ADS represents ten ordinary shares and that all trades were executed pursuant to a Rule 10b5-1 trading plan adopted on November 11, 2025, indicating the sales were pre-scheduled rather than opportunistic.

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
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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^*

Du Ying

(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)

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

3. Date of Earliest Transaction (Month/Day/Year)
03/06/2026

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)	03/06/2026		M		50,000	A	$1.74	1,014,161	D
American Depositary Shares(1)	03/06/2026		S(2)		50,000	D	$19.4187(3)	964,161	D
American Depositary Shares(1)	03/09/2026		M		50,000	A	$1.74	1,014,161	D
American Depositary Shares(1)	03/09/2026		S(2)		50,000	D	$19.0293(4)	964,161	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
Stock Options (Right to Buy)	$1.74	03/06/2026		M			50,000	(5)	08/25/2026	American Depositary Shares(1)	50,000	$0	772,184	D
Stock Options (Right to Buy)	$1.74	03/09/2026		M			50,000	(5)	08/25/2026	American Depositary Shares(1)	50,000	$0	722,184	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. The transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on November 11, 2025.

3. Reflects a weighted average sale price of $19.4187 per share, at prices ranging from $19.04 to $19.68 per share. The Reporting Person will provide, upon request by the staff of the Securities and Exchange Commission, the Issuer, or a security holder of the Issuer, full information regarding the number of shares sold at each separate price.

4. Reflects a weighted average sale price of $19.0293 per share, at prices ranging from $18.78 to $19.25 per share. The Reporting Person will provide, upon request by the staff of the Securities and Exchange Commission, the Issuer, or a security holder of the Issuer, full information regarding the number of shares sold at each separate price.

5. The option vested in equal annual installments over five years beginning on August 25, 2017, the first anniversary of the date of grant.

	/s/ Bruce Blefeld, Attorney-in-Fact	03/10/2026
	** 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).
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FAQ

What insider transactions did Zai Lab (ZLAB) report for Du Ying?

Du Ying exercised stock options for 100,000 American Depositary Shares and sold 100,000 ADS in open-market transactions. These moves combined option exercises with share disposals while leaving a sizable remaining direct holding of 964,161 ADS after the reported trades.

At what prices did Du Ying sell Zai Lab (ZLAB) ADS in this Form 4?

Du Ying sold 50,000 American Depositary Shares at a weighted average price of $19.4187 and another 50,000 ADS at $19.0293. Each sale covered multiple trades within indicated price ranges, as detailed in the weighted-average footnotes.

How many Zai Lab (ZLAB) shares does Du Ying own after these transactions?

After the reported option exercises and sales, Du Ying directly owns 964,161 American Depositary Shares. This figure reflects the position remaining following the two 50,000-ADS sales executed on March 6 and March 9, 2026 under the disclosed trading plan.

Were Du Ying’s Zai Lab (ZLAB) transactions part of a Rule 10b5-1 plan?

Yes. The filing states all transactions were effected under a Rule 10b5-1 trading plan adopted on November 11, 2025. Such pre-arranged plans schedule trades in advance, reducing the significance of short-term market timing in interpreting these sales.

What type of securities did Du Ying exercise and sell for Zai Lab (ZLAB)?

Du Ying exercised stock options with a right to buy 100,000 American Depositary Shares at $1.74 per ADS and then sold 100,000 ADS. Each ADS represents ten ordinary shares of Zai Lab, and the company’s ADSs and ordinary shares are fully fungible.

Over what period did Du Ying’s exercised Zai Lab (ZLAB) options vest?

The stock option exercised in these transactions vested in equal annual installments over five years beginning August 25, 2017. That schedule reflects long-term compensation that became exercisable over time before being converted into American Depositary Shares.