Zai Lab CEO sells 100K ADS after option exercise

Zai Lab Ltd Chairperson and CEO Du Ying reported option exercises and share sales in American Depositary Shares (ADS).

Rhea-AI Filing Summary

Zai Lab Ltd Chairperson and CEO Du Ying reported option exercises and share sales in American Depositary Shares (ADS). On May 15 and May 18, Du Ying exercised stock options to acquire a total of 100,000 ADS at an exercise price of $1.74 per ADS and sold 100,000 ADS in open-market transactions.

The reported weighted average sale prices were $20.7422 and $18.9953 per ADS, with individual trades executed within disclosed price ranges. These trades were carried out under a pre-arranged Rule 10b5-1 trading plan adopted on November 11, 2025. Following the transactions, Du Ying directly holds 1,122,626 ADS.

Insider Trade Summary 10b5-1

Exercise and Sale: 100,000 shares ($1.81M approx. pre-tax spread)

Exercise and Sale 6 txns

Insider Du Ying

Role Chairperson & CEO

Sold 100,000 shs ($1.99M)

Approx. gross sale proceeds $1.99M

Approx. exercise cost $174K

Approx. pre-tax spread $1.81M

Type	Security	Shares	Price	Value
Exercise	Stock Options (Right to Buy)	50,000	$0.00	$0.00
Exercise	American Depositary Shares	50,000	$1.74	$87K
Sale	American Depositary Shares	50,000	$18.9953	$950K
Exercise	Stock Options (Right to Buy)	50,000	$0.00	$0.00
Exercise	American Depositary Shares	50,000	$1.74	$87K
Sale	American Depositary Shares	50,000	$20.7422	$1.04M

Holdings After Transaction: Stock Options (Right to Buy) — 261,092 contracts (Direct); American Depositary Shares — 1,122,626 shares (Direct)

Footnotes (5)

1. F1. 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. F2. 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. F3. Reflects a weighted average sale price of $20.7422 per share, at prices ranging from $20.417 to $21.28 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. F4. Reflects a weighted average sale price of $18.9953 per share, at prices ranging from $18.78 to $19.38 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. F5. The option vested in equal annual installments over five years beginning on August 25, 2017, the first anniversary of the date of grant.

Key Figures

ADS sold: 100,000 ADS Weighted average sale price (day 1): $20.7422 per ADS Weighted average sale price (day 2): $18.9953 per ADS +5 more

8 metrics

ADS sold 100,000 ADS Total open-market sales reported across May 15 and May 18, 2026

Weighted average sale price (day 1) $20.7422 per ADS Open-market sale price on May 15, 2026

Weighted average sale price (day 2) $18.9953 per ADS Open-market sale price on May 18, 2026

Options exercise price $1.74 per ADS Exercise price for stock options converted into ADS

ADS acquired via option exercise 100,000 ADS Total ADS obtained through stock option exercises

Post-transaction ADS holdings 1,122,626 ADS Direct holdings after latest reported transaction

Option expiration date August 25, 2026 Expiration date for the reported stock options

ADS to Ordinary Share ratio 1 ADS = 10 Ordinary Shares Representation of issuer’s Ordinary Shares per ADS

Key Terms

American Depositary Shares, Rule 10b5-1 trading plan, Stock Options (Right to Buy), weighted average sale price, +1 more

5 terms

American Depositary Shares financial

"Each American Depositary Share ("ADS") represents ten Ordinary Shares of the issuer."

American depositary shares (ADSs) are a way for investors in the United States to buy shares of foreign companies without dealing with international markets directly. They represent ownership in a foreign company's stock and are traded on U.S. stock exchanges, making it easier for American investors to buy, sell, and own parts of companies from around the world.

Rule 10b5-1 trading plan regulatory

"The transactions reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person."

A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.

Stock Options (Right to Buy) financial

"Stock Options (Right to Buy) with an exercise price of $1.7400 and expiration date August 25, 2026."

weighted average sale price financial

"Reflects a weighted average sale price of $20.7422 per share, at prices ranging from $20.417 to $21.28 per share."

fully fungible financial

"Our ADSs and Ordinary Shares are fully fungible."

FAQ

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

Du Ying reported exercising stock options for 100,000 American Depositary Shares (ADS) at $1.74 per ADS and selling 100,000 ADS in open-market trades. These combined transactions reflect an exercise-and-sell pattern over two trading days.

How many Zai Lab (ZLAB) ADS did the CEO sell and at what prices?

Du Ying sold 100,000 American Depositary Shares in total. Weighted average sale prices were $20.7422 per ADS on one day and $18.9953 per ADS on another, with individual trades executed within the disclosed price ranges around those averages.

What stock options did Zai Lab (ZLAB) CEO exercise in this Form 4?

The CEO exercised stock options covering 100,000 American Depositary Shares at a conversion or exercise price of $1.74 per ADS. The options vested in equal annual installments over five years beginning on August 25, 2017, according to the disclosure footnote.

How many Zai Lab (ZLAB) ADS does the CEO hold after these trades?

After the reported option exercises and share sales, Du Ying directly holds 1,122,626 American Depositary Shares. This figure reflects the holding reported immediately following the latest transaction date shown in the Form 4 filing excerpt.

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

Yes. The filing states the transactions were executed pursuant to a Rule 10b5-1 trading plan adopted on November 11, 2025. Such plans pre-schedule trades, making the timing more mechanical rather than discretionary day-to-day trading decisions.

What does one Zai Lab (ZLAB) American Depositary Share represent?

Each American Depositary Share represents ten Ordinary Shares of Zai Lab Ltd. The filing notes that the company’s ADSs and Ordinary Shares are fully fungible, and all amounts in this Form 4 are reported in terms of ADSs for consistency.

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Accepted by SEC EDGAR 05/19/2026 - 04:18 PM Learn about SEC filing dates

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^*

Du Ying

(Last) (First) (Middle)

C/O ZAI LAB LIMITED

314 MAIN STREET, 4TH FLOOR, SUITE 100

(Street)

CAMBRIDGE MASSACHUSETTS 02142

(City) (State) (Zip)

UNITED STATES

(Country)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/15/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

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

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)	05/15/2026		M(2)		50,000	A	$1.74	1,172,626	D
American Depositary Shares(1)	05/15/2026		S(2)		50,000	D	$20.7422(3)	1,122,626	D
American Depositary Shares(1)	05/18/2026		M(2)		50,000	A	$1.74	1,172,626	D
American Depositary Shares(1)	05/18/2026		S(2)		50,000	D	$18.9953(4)	1,122,626	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	05/15/2026		M(2)			50,000	(5)	08/25/2026	American Depositary Shares(1)	50,000	$0	311,092	D
Stock Options (Right to Buy)	$1.74	05/18/2026		M(2)			50,000	(5)	08/25/2026	American Depositary Shares(1)	50,000	$0	261,092	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 $20.7422 per share, at prices ranging from $20.417 to $21.28 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 $18.9953 per share, at prices ranging from $18.78 to $19.38 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	05/19/2026
	** 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).
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 4: SEC 1474 (03-26)