Zai Lab (ZLAB) CEO trades 100K ADS under 10b5-1 plan

Rhea-AI Filing Summary

Zai Lab Ltd chairperson and CEO Du Ying reported exercising stock options and selling shares in early March 2026. On March 4–5, 2026, Du Ying exercised options for a total of 100,000 American Depositary Shares (ADS), described as derivative exercises or conversions at $1.74 per ADS.

Over the same two days, Du Ying sold 100,000 ADS in open-market transactions at weighted average prices of $18.7769, $19.3176, and $19.2211 per ADS. After these trades, Du Ying directly owned 964,161 ADS. Each ADS represents ten ordinary shares, and all trades were executed under a pre-arranged Rule 10b5-1 trading plan adopted on November 11, 2025.

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

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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)
03/04/2026

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)	03/04/2026		M		50,000	A	$1.74	1,014,161	D
American Depositary Shares(1)	03/04/2026		S(2)		14,290	D	$18.7769(3)	999,871	D
American Depositary Shares(1)	03/04/2026		S(2)		35,710	D	$19.3176(4)	964,161	D
American Depositary Shares(1)	03/05/2026		M		50,000	A	$1.74	1,014,161	D
American Depositary Shares(1)	03/05/2026		S(2)		50,000	D	$19.2211(5)	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	03/04/2026		M			50,000	(6)	08/25/2026	American Depositary Shares(1)	50,000	$0	872,184	D
Stock Options (Right to Buy)	$1.74	03/05/2026		M			50,000	(6)	08/25/2026	American Depositary Shares(1)	50,000	$0	822,184	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 $18.7769 per share, at prices ranging from $18.09 to $19.085 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 $19.3176 per share, at prices ranging from $19.09 to $19.50 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. Reflects a weighted average sale price of $19.2211 per share, at prices ranging from $18.89 to $19.395 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.

6. 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	03/06/2026
	** 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).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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FAQ

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

Zai Lab reported that chairperson and CEO Du Ying exercised options for 100,000 ADS and sold 100,000 ADS in open-market trades on March 4–5, 2026. All transactions were made under a pre-established Rule 10b5-1 trading plan.

How many Zai Lab (ZLAB) ADS does Du Ying hold after these transactions?

After completing the March 4–5, 2026 option exercises and share sales, Du Ying directly holds 964,161 American Depositary Shares of Zai Lab. Each ADS represents ten ordinary shares, making this a significant continuing ownership position in the company.

At what prices did Du Ying sell Zai Lab (ZLAB) ADS?

Du Ying’s reported Zai Lab ADS sales used weighted average prices of $18.7769, $19.3176, and $19.2211 per ADS. The filing notes these averages reflect multiple individual trades within specified price ranges on March 4–5, 2026, in open-market transactions.

Were Du Ying’s Zai Lab (ZLAB) trades under a Rule 10b5-1 plan?

Yes. The Form 4 states that all reported transactions were effected under a Rule 10b5-1 trading plan adopted by Du Ying on November 11, 2025. Such plans pre-schedule trades, helping separate them from day-to-day discretionary trading decisions.

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

Du Ying exercised stock options that converted into American Depositary Shares and then sold ADS in the open market. Each ADS represents ten ordinary shares of Zai Lab, and the filing reports all quantities and prices in terms of ADS.

How many Zai Lab (ZLAB) ADS did Du Ying sell in total?

Across the reported March 4–5, 2026 transactions, Du Ying sold a total of 100,000 American Depositary Shares in open-market or private transactions. These sales were executed at disclosed weighted average prices near $19 per ADS, according to the Form 4.