Form 4: Ardelyx officer reports automatic RSU tax share sale

Rhea-AI Filing Summary

Ardelyx, Inc. (ARDX) reported a Form 4 filing for its Chief Commercial Officer, who is an officer but not a 10% owner. On 11/21/2025, the officer sold 5,814 shares of Ardelyx common stock at a price of $5.5369 per share. According to the explanation, the sale was an automatic sell-to-cover triggered by the vesting of restricted stock units, with shares sold solely to cover withholding taxes. Following this transaction, the officer directly beneficially owns 295,684 shares of Ardelyx common stock.

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

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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).

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^*

Foster Eric Duane

(Last) (First) (Middle)

C/O ARDELYX, INC.

400 FIFTH AVENUE, SUITE 210

(Street)

WALTHAM MA 02451

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
ARDELYX, INC. [ ARDX ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
11/21/2025

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	11/21/2025		S(1)		5,814	D	$5.5369	295,684	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

Explanation of Responses:

1. Pursuant to an automatic sell-to-cover imposed by the terms of the initial grant of the restricted stock units ("RSUs") awards, the shares were sold upon the vesting of the RSUs solely to cover applicable withholding taxes.

	/s/ Elizabeth Grammer, Attorney-in-fact for Eric D. Foster	11/25/2025
	** 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.

FAQ

What did Ardelyx (ARDX) disclose in this Form 4 filing?

The filing reports that Ardelyx's Chief Commercial Officer sold 5,814 shares of common stock on 11/21/2025 as part of an automatic tax withholding transaction tied to restricted stock unit vesting.

Who is the reporting person in the Ardelyx (ARDX) Form 4?

The reporting person is an officer of Ardelyx, Inc., serving as Chief Commercial Officer, and the form is filed for one reporting person.

How many Ardelyx (ARDX) shares were sold and at what price?

The officer sold 5,814 shares of Ardelyx common stock at a price of $5.5369 per share on 11/21/2025.

How many Ardelyx (ARDX) shares does the officer own after the transaction?

After the reported sale, the officer beneficially owns 295,684 shares of Ardelyx common stock in direct ownership.

Why were the Ardelyx (ARDX) shares sold in this Form 4?

The explanation states that, under an automatic sell-to-cover provision in the restricted stock unit (RSU) grant, shares were sold upon RSU vesting solely to cover applicable withholding taxes.

Does this Ardelyx (ARDX) Form 4 involve any derivative securities?

The section for derivative securities is included in the form but shows no reported derivative transactions in the provided content.