PTGX director exercises options, sells 18,000 shares

Protagonist Therapeutics (PTGX) director Williams Lewis T reported exercising stock options and selling shares.

Rhea-AI Filing Summary

Protagonist Therapeutics (PTGX) director Williams Lewis T reported exercising stock options and selling shares. On February 17, 2026, he exercised 18,000 stock options at a price of $10.84 per share, converting them into 18,000 shares of common stock. The options are fully vested.

That same day, he sold 18,000 common shares in open-market transactions at a weighted average price of $82.42 per share, with individual trade prices ranging from $81.47 to $83.12. After these transactions, he directly holds 7,825 common shares and 6,000 stock options.

Insider Trade Summary

Exercise and Sale: 18,000 shares ($1.29M approx. pre-tax spread)

Exercise and Sale 3 txns

Insider Williams Lewis T

Role Director

Sold 18,000 shs ($1.48M)

Approx. gross sale proceeds $1.48M

Approx. exercise cost $195K

Approx. pre-tax spread $1.29M

Type	Security	Shares	Price	Value
Exercise	Stock Option (right to buy)	18,000	$0.00	$0.00
Exercise	Common Stock	18,000	$10.84	$195K
Sale	Common Stock	18,000	$82.42	$1.48M

Holdings After Transaction: Stock Option (right to buy) — 6,000 contracts (Direct); Common Stock — 7,825 shares (Direct)

Footnotes (2)

1. F1. The price reported represents the weighted average sale price per share. The shares were sold in multiple transactions at prices ranging from $81.47 to $83.12. Upon request by the staff of the U.S. Securities and Exchange Commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.
2. F2. These stock options are fully vested.

FAQ

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What insider transactions did PTGX director Williams Lewis T report?

He reported exercising 18,000 stock options and selling 18,000 common shares on February 17, 2026. The exercise converted options at $10.84 per share into stock, followed by open-market sales at a weighted average price of $82.42 per share.

At what prices were the Protagonist Therapeutics (PTGX) shares sold?

The 18,000 PTGX shares were sold at a weighted average price of $82.42 per share. Individual trades occurred in multiple transactions, with prices ranging from $81.47 to $83.12, according to the weighted-average pricing footnote.

How many Protagonist Therapeutics (PTGX) shares and options does Williams Lewis T own after the Form 4?

Following these transactions, he directly holds 7,825 shares of PTGX common stock. He also holds 6,000 stock options, which remain outstanding after exercising 18,000 options that were fully vested at the time of exercise.

What type of derivative transaction was reported in the PTGX Form 4?

The filing shows an exercise of stock options, classified as an exercise or conversion of a derivative security. Williams Lewis T exercised 18,000 fully vested options at $10.84 per share, receiving an equal number of PTGX common shares.

Was the PTGX insider sale an open-market transaction?

Yes. The Form 4 classifies the 18,000-share sale as an open-market or private transaction under code “S.” The sale used a weighted average price of $82.42, with individual trades executed between $81.47 and $83.12 per share.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Accepted by SEC EDGAR 02/18/2026 - 06:12 PM EST 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).

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^*

Williams Lewis T

(Last) (First) (Middle)

C/O PROTAGONIST THERAPEUTICS, INC.

7707 GATEWAY BLVD., SUITE 140

(Street)

NEWARK CA 94560-1160

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Protagonist Therapeutics, Inc [ PTGX ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
02/17/2026

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
Common Stock	02/17/2026		M		18,000	A	$10.84	25,825	D
Common Stock	02/17/2026		S		18,000	D	$82.42(1)	7,825	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 Option (right to buy)	$10.84	02/17/2026		M		18,000		(2)	06/15/2027	Common Stock	18,000	$0	6,000	D

Explanation of Responses:

1. The price reported represents the weighted average sale price per share. The shares were sold in multiple transactions at prices ranging from $81.47 to $83.12. Upon request by the staff of the U.S. Securities and Exchange Commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.

2. These stock options are fully vested.

	/s/ Matthew Gosling, Attorney-in-Fact for Lewis T. "Rusty" Williams	02/18/2026
	** 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.