Ardelyx (NASDAQ: ARDX) exec plans 10,500-share RSU tax sale

Rhea-AI Filing Summary

Ardelyx, Inc. (ARDX) is the issuer in a Form 144 notice filed for planned sales of its common stock by officer Mike Kelliher. The notice covers 10,500 shares of common stock, with an approximate aggregate market value of $42,315.00, to be sold through Morgan Stanley Smith Barney LLC on NASDAQ. The shares relate to RSUs vesting on 08/19/2026 and are to be sold solely under an automatic sell-to-cover feature to satisfy applicable withholding taxes. Ardelyx reports 249,187,572 common shares outstanding in connection with this notice.

Key Figures

Shares proposed to be sold: 10,500 shares of Common Stock Aggregate market value of proposed sale: $42,315.00 Shares outstanding: 249,187,572 shares of Common Stock +5 more

8 metrics

Shares proposed to be sold 10,500 shares of Common Stock Planned sale of Ardelyx common stock under Form 144

Aggregate market value of proposed sale $42,315.00 Approximate market value for 10,500 shares of Common Stock

Shares outstanding 249,187,572 shares of Common Stock Ardelyx common shares outstanding referenced in the notice

RSUs vesting amount 24,986 shares Vesting of restricted stock units on 08/19/2026

Past sale 1 2,900 shares for $18,175.75 Common Stock sale on 05/21/2026 by Mike Kelliher

Past sale 2 1,870 shares for $11,720.23 Common Stock sale on 05/21/2026 by Mike Kelliher

Past sale 3 2,478 shares for $15,530.87 Common Stock sale on 05/21/2026 by Mike Kelliher

Date of Notice 08/21/2026 Filing date of the Form 144 notice

Key Terms

Rule 144, restricted stock units, sell-to-cover, withholding taxes

4 terms

Rule 144 regulatory

"See the definition of "person" in paragraph (a) of Rule 144."

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

restricted stock units financial

"Vesting of restricted stock units | Issuer | | | 24986"

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

sell-to-cover financial

"Pursuant to an automatic sell-to-cover imposed by the terms of the initial grant"

Sell-to-cover is when part of newly issued or exercised company stock is immediately sold to pay required taxes and fees, so the recipient keeps the remaining shares. For investors this matters because it reduces the number of shares insiders or employees actually hold after a grant, can create small, routine share sales that aren’t signal of cashing out, and slightly increases share supply on the market—like selling a portion of a paycheck to cover the tax bill.

withholding taxes financial

"the shares are to be sold upon the vesting of the RSUs solely to cover applicable withholding taxes."

Withholding taxes are amounts a payer or government takes out of payments — such as wages, interest, or dividends — before the recipient gets the money, functioning like a cashier keeping part of a bill to pay taxes on your behalf. For investors this matters because it reduces the cash they actually receive, affects net returns and yield calculations, and may require additional paperwork or treaty claims to recover or offset the withheld amount against final tax bills.

FAQ

What is the purpose of the Form 144 filing for ARDX?

The Form 144 relates to planned sales of Ardelyx (ARDX) common stock by officer Mike Kelliher. Shares from vested RSUs are to be sold under an automatic sell-to-cover arrangement solely to cover applicable withholding taxes associated with the RSU vesting.

How many Ardelyx (ARDX) shares are proposed to be sold under this Form 144?

The notice covers a proposed sale of 10,500 shares of Ardelyx common stock. The filing lists an approximate aggregate market value of $42,315.00 for these shares, to be sold through Morgan Stanley Smith Barney LLC on NASDAQ.

What is the source of the Ardelyx (ARDX) shares being sold under this Form 144?

The shares come from the vesting of restricted stock units (RSUs) on 08/19/2026. The filing states the vesting amount as 24,986 shares, with a portion to be automatically sold solely to cover withholding taxes under the grant terms.

How many Ardelyx (ARDX) shares were sold by Mike Kelliher in the past three months?

Over the past three months, Mike Kelliher reported three sales of Ardelyx common stock on 05/21/2026: 2,900 shares for $18,175.75, 1,870 shares for $11,720.23, and 2,478 shares for $15,530.87.

How many Ardelyx (ARDX) common shares are outstanding according to this Form 144?

The Form 144 lists 249,187,572 Ardelyx common shares outstanding. This figure provides context for the proposed 10,500-share sale; it is a baseline figure for the company’s equity and not the amount being sold.

Who is the broker handling the Form 144 sale for Ardelyx (ARDX) shares?

The proposed sale of 10,500 Ardelyx (ARDX) common shares is to be executed through Morgan Stanley Smith Barney LLC Executive Financial Services, located at 1 New York Plaza, New York, as listed in the Form 144 filing.

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Available on EDGAR 08/21/2026 - 08:26 PM Accepted by SEC EDGAR 08/21/2026 - 08:25 PM Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001987188
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	ARDELYX, INC.
SEC File Number	001-36485
Address of Issuer	400 Fifth Avenue, Suite 210 Waltham MASSACHUSETTS 02451
Phone	617 675-2739
Name of Person for Whose Account the Securities are To Be Sold	Kelliher Mike
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Officer

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common Stock	Morgan Stanley Smith Barney LLC Executive Financial Services 1 New York Plaza, 8th Floor New York NY 10004	10500	42315.00	249187572	08/21/2026	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common Stock	08/19/2026	Vesting of restricted stock units	Issuer			24986	08/19/2026	Services Rendered

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
Mike Kelliher 400 Fifth Avenue, Suite 210 Waltham MA 02451	Common Stock	05/21/2026	2900	18175.75
Mike Kelliher 400 Fifth Avenue, Suite 210 Waltham MA 02451	Common Stock	05/21/2026	1870	11720.23
Mike Kelliher 400 Fifth Avenue, Suite 210 Waltham MA 02451	Common Stock	05/21/2026	2478	15530.87

144: Remarks and Signature

Remarks	Pursuant to an automatic sell-to-cover imposed by the terms of the initial grant of the restricted stock units (RSUs) awards, the shares are to be sold upon the vesting of the RSUs solely to cover applicable withholding taxes.
Date of Notice	08/21/2026
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	Orlando Wells
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)