Equity awards lift Zai Lab (ZLAB) officer’s ADS stake despite tax sale

Rhea-AI Filing Summary

Zai Lab Ltd officer Joshua L. Smiley reported multiple equity compensation transactions involving American Depositary Shares (ADSs) and share units. On April 1, 2026, RSUs vested into 32,062 ADSs, and on April 2, 2026, additional RSUs vested into 7,145 ADSs, each RSU converting into one ADS at a price of $0.00 per unit.

On April 2, 2026, 9,614 ADSs were sold at $20.39 per ADS, with a footnote stating these shares were sold automatically to cover taxes upon RSU vesting. After these transactions, Smiley directly owned 120,619 ADSs. Separately, on March 4, 2026, he was credited with 17,887 performance-based share units, each representing a contingent right to receive one ADS, following satisfaction of 2025 performance criteria; these PSUs vest in full on March 12, 2028 subject to continuous service. RSUs referenced in the filing vest in equal annual installments over four years, with vested shares delivered in ADS form.

Insider Trade Summary

Net Seller: 9,614 shares ($196,029)

Net Sell 6 txns

Insider Smiley Joshua L

Role See Remarks

Sold 9,614 shs ($196K)

Type	Security	Shares	Price	Value
Exercise	Restricted Share Units	7,145	$0.00	--
Exercise	American Depositary Shares	7,145	$0.00	--
Sale	American Depositary Shares	9,614	$20.39	$196K
Exercise	Restricted Share Units	32,062	$0.00	--
Exercise	American Depositary Shares	32,062	$0.00	--
Grant/Award	Performance-Based Share Units	17,887	$0.00	--

Holdings After Transaction: Restricted Share Units — 7,145 shares (Direct); American Depositary Shares — 130,233 shares (Direct); Performance-Based Share Units — 17,887 shares (Direct)

Footnotes (1)

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. ADSs acquired upon vesting of Restricted Share Units ("RSUs"). Each RSU represents a contingent right to receive one ADS. These ADSs were sold automatically to cover taxes upon vesting of RSUs. Each performance-based share unit ("PSU") represents a contingent right to receive one ADS. The reporting person was granted PSUs on March 12, 2025 based on the satisfaction of specified performance criteria between January 1, 2025 through December 31, 2025. On March 4, 2026, the performance-based vesting conditions were confirmed for PSUs representing 17,887 ADSs. The PSUs vest in full on March 12, 2028, the third anniversary of the date of grant, subject to continuous service. The RSUs vest in equal annual installments over four years beginning on 04/01/2025, the first anniversary of the date of grant, subject to continuous service. Vested shares will be delivered in the form of ADSs to the reporting person following vesting. The RSUs vest in equal annual installments over four years beginning on 04/03/2024, the first anniversary of the date of grant, subject to continuous service. Vested shares will be delivered in the form of ADSs to the reporting person following vesting.

Key Figures

RSUs vested to ADSs on April 1, 2026: 32,062 ADSs at $0.00 RSUs vested to ADSs on April 2, 2026: 7,145 ADSs at $0.00 ADSs sold to cover taxes: 9,614 ADSs at $20.39 +4 more

7 metrics

RSUs vested to ADSs on April 1, 2026 32,062 ADSs at $0.00 Conversion of Restricted Share Units into American Depositary Shares

RSUs vested to ADSs on April 2, 2026 7,145 ADSs at $0.00 Additional RSU vesting and conversion into ADSs

ADSs sold to cover taxes 9,614 ADSs at $20.39 Automatic sale on April 2, 2026 to satisfy tax obligations

Direct ADS holdings after transactions 120,619 ADSs Direct ownership following April 2, 2026 transactions

Performance-based share units granted 17,887 PSUs Contingent right to receive ADSs; vesting on March 12, 2028

RSU balance after April 1, 2026 64,125 RSUs Restricted Share Units remaining after derivative transaction on April 1, 2026

ADS-to-ordinary share ratio 1 ADS = 10 ordinary shares Capital structure detail from footnote F1

Key Terms

Restricted Share Units, Performance-Based Share Units, American Depositary Shares, contingent right, +2 more

6 terms

Restricted Share Units financial

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

Restricted share units (RSUs) are a promise from a company to give an employee or service provider actual shares or cash equal to the shares after certain conditions are met, typically staying with the company for a set time or hitting performance targets. Think of them like a time-locked gift card that becomes usable only after you’ve earned it. For investors, RSUs matter because they align employee incentives with company performance and can increase the number of shares outstanding over time, diluting existing ownership and affecting earnings per share.

Performance-Based Share Units financial

"Each performance-based share unit ("PSU") represents a contingent right to receive one ADS."

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.

contingent right financial

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

vest in equal annual installments financial

"The RSUs vest in equal annual installments over four years beginning on 04/01/2025."

continuous service financial

"The PSUs vest in full on March 12, 2028 ... subject to continuous service."

Form 4 Insider Transactions: What Each Field Means →

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).

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^*

Smiley Joshua L

(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)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	See Remarks

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
03/04/2026

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)	04/01/2026		M		32,062(2)	A	(3)	123,088	D
American Depositary Shares(1)	04/02/2026		M		7,145(2)	A	(3)	130,233	D
American Depositary Shares(1)	04/02/2026		S		9,614(4)	D	$20.39	120,619	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
Performance-Based Share Units	(5)	03/04/2026		A		17,887		(6)	(6)	American Depositary Shares(1)	17,887	$0	17,887	D
Restricted Share Units	(3)	04/01/2026		M			32,062	(7)	(7)	American Depositary Shares(1)	32,062	$0	64,125	D
Restricted Share Units	(3)	04/02/2026		M			7,145	(8)	(8)	American Depositary Shares(1)	7,145	$0	7,145	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. Each performance-based share unit ("PSU") represents a contingent right to receive one ADS.

6. The reporting person was granted PSUs on March 12, 2025 based on the satisfaction of specified performance criteria between January 1, 2025 through December 31, 2025. On March 4, 2026, the performance-based vesting conditions were confirmed for PSUs representing 17,887 ADSs. The PSUs vest in full on March 12, 2028, the third anniversary of the date of grant, subject to continuous service.

7. The RSUs vest in equal annual installments over four years beginning on 04/01/2025, the first anniversary of the date of grant, subject to continuous service. Vested shares will be delivered in the form of ADSs to the reporting person following vesting.

8. The RSUs vest in equal annual installments over four years beginning on 04/03/2024, the first anniversary of the date of grant, subject to continuous service. Vested shares will be delivered in the form of ADSs to the reporting person following vesting.

Remarks:

President and Chief Operating Officer

	/s/ Bruce Blefeld, Attorney-in-Fact	04/03/2026
	** 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)

FAQ

What insider transactions did Joshua L. Smiley report at Zai Lab (ZLAB)?

Joshua L. Smiley reported RSU vesting into ADSs, an automatic tax-related sale, and a new PSU award. RSUs converted into 32,062 ADSs on April 1, 2026 and 7,145 ADSs on April 2, 2026, with 9,614 ADSs sold to cover taxes.

How many Zai Lab (ZLAB) ADSs did Smiley own after these Form 4 transactions?

After the reported transactions, Joshua L. Smiley directly owned 120,619 American Depositary Shares. This figure reflects RSU vesting into ADSs on April 1 and April 2, 2026, along with the 9,614 ADSs automatically sold to cover tax obligations tied to the vesting.

Were Joshua L. Smiley’s Zai Lab (ZLAB) share sales open-market trades?

The filing shows a sale of 9,614 ADSs at $20.39 per share on April 2, 2026. A footnote explains these ADSs were sold automatically to cover taxes upon RSU vesting, indicating a tax-withholding mechanism rather than a discretionary open-market sale for investment reasons.

What performance-based share units did Smiley receive from Zai Lab (ZLAB)?

On March 4, 2026, Smiley was credited with 17,887 performance-based share units. A footnote explains these PSUs were granted on March 12, 2025, tied to 2025 performance, and will vest in full on March 12, 2028, subject to his continuous service with the company.

How do Zai Lab (ZLAB) RSUs and PSUs convert into ADSs for Joshua L. Smiley?

Each RSU and each performance-based share unit represents a contingent right to receive one ADS. RSUs vest in equal annual installments over four years, delivering ADSs upon vesting, while the 17,887 PSUs vest in full on March 12, 2028, assuming continued service.

What is the ADS-to-ordinary share ratio for Zai Lab (ZLAB) in this filing?

The filing states that each American Depositary Share represents ten ordinary shares of Zai Lab. It also notes that the company’s ADSs and ordinary shares are fully fungible and that the Form 4 reports all equity holdings and transactions in terms of ADSs for consistency.