[Form 4] Ionis Pharmaceuticals, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Patrick R. O'Neil, EVP, CLO & General Counsel of Ionis Pharmaceuticals (IONS), reported a non-derivative purchase of 331 shares of Ionis common stock on 08/29/2025 at a price of $27.71 per share under the company's Amended and Restated 2000 Employee Stock Purchase Plan. After the purchase O'Neil beneficially owned 57,130 shares. The filing notes these ESPP-acquired shares may not be sold until 03/02/2026. The Form 4 is a single-person filing and reflects a routine employee-plan purchase rather than a sale or option exercise.

Positive

• Insider participation via the company's ESPP indicates alignment with employee ownership programs
• Full disclosure of purchase price, quantity, and post-transaction beneficial ownership demonstrates compliance with Section 16 reporting

Negative

• None.

Insights

Securities Analyst

TL;DR: Insider purchased 331 shares under ESPP; modest insider buy with sale restriction until March 2026.

The transaction is a standard ESPP acquisition at $27.71 per share for 331 shares, increasing the reporting person's beneficial ownership to 57,130 shares. This filing does not disclose any derivative transactions or dispositions. As an ESPP purchase, it is a prearranged employee-plan acquisition and carries a holding restriction until 03/02/2026, which limits immediate market impact. The size of the purchase is small relative to typical institutional moves and therefore unlikely to be material to valuation.

Corporate Governance Expert

TL;DR: Routine, compliant insider disclosure of an ESPP purchase with required lock-up statement; governance process appears followed.

The Form 4 properly identifies the reporting person, relationship to the issuer (Officer: EVP, CLO & General Counsel), and details of the non-derivative purchase. The filing specifies the program-based purchase and the restriction on sale until 03/02/2026, fulfilling disclosure requirements for Section 16 insiders. There is no indication of related-party transactions or amendments; the filing format and signature indicate standard compliance with filing rules.

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
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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^*

O'NEIL PATRICK R.

(Last) (First) (Middle)

2855 GAZELLE COURT

(Street)

CARLSBAD CA 92010

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
IONIS PHARMACEUTICALS INC [ IONS ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP CLO & General Counsel

3. Date of Earliest Transaction (Month/Day/Year)
08/29/2025

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	08/29/2025		J		331(1)	A	$27.71	57,130	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. Reporting shares purchased under the Ionis Pharmaceuticals, Inc. Amended and Restated 2000 Employee Stock Purchase Plan on August 29, 2025. These shares may not be sold until March 2, 2026.

	Patrick O'Neil	09/03/2025
	** 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 transaction did Patrick R. O'Neil report for IONS?

He reported purchasing 331 shares of Ionis common stock on 08/29/2025 at $27.71 per share under the company's ESPP.

How many Ionis shares does Patrick O'Neil beneficially own after the transaction?

The filing reports 57,130 shares beneficially owned following the reported transaction.

Are there any selling restrictions on the shares purchased?

Yes. The ESPP-acquired shares may not be sold until 03/02/2026, as stated in the Form 4 explanation.

What is Patrick O'Neil's role at Ionis as listed on the Form 4?

He is listed as an Officer with the title EVP, CLO & General Counsel.

Was this Form 4 filed by more than one reporting person?

No. The form indicates it was filed by one reporting person.