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

Rhea-AI Filing Summary

Insider transactions by Patrick R. O'Neil, EVP, CLO & General Counsel of Ionis Pharmaceuticals (IONS): The Form 4 reports multiple transactions dated 09/09/2025 showing both acquisitions and dispositions of Ionis common stock and related options. The reporting person acquired 21,000 shares (20,000 and 1,000) via option-related transactions at exercise prices shown and sold 21,000 shares under a Rule 10b5-1 trading plan at a weighted average sale price of $64.5553 per share. Following the reported activity the filer beneficially owns between 57,130 and 77,203 shares depending on the line item.

The filing discloses that the sales were made pursuant to a 10b5-1 plan adopted May 2, 2025, and that the reported sale price is a weighted average reflecting multiple executions between $64.50 and $64.66. The filer offers to provide detailed per-trade prices on request.

Positive

• Full disclosure of 10b5-1 plan including adoption date (May 2, 2025) and statement to provide detailed per-trade prices on request
• Weighted-average sale price disclosed ($64.5553) along with the execution range ($64.50–$64.66), improving transparency
• Reporting includes option exercise details with exercise prices ($56.78 and $60.89) and resulting share counts

Negative

• None.

Insights

Securities Analyst

TL;DR: Insider both exercised options and sold shares under a 10b5-1 plan; transactions are disclosed and weighted-average sale price provided.

The Form 4 documents contemporaneous option exercise-related acquisitions and planned sales executed under a Rule 10b5-1 plan. The reporting person acquired 21,000 shares via option-related entries (exercises at $56.78 and $60.89 shown) while selling 21,000 shares at a weighted average of $64.5553 per share. The filing transparently notes the 10b5-1 plan adoption date and discloses the sale price range ($64.50–$64.66). For investors, this is a routine insider liquidity event with clear disclosure; no additional financial results or corporate action is reported here.

Corporate Governance Expert

TL;DR: Disclosure aligns with Section 16 reporting and documents a Rule 10b5-1 plan sale; presentation appears complete for the transactions stated.

The Form 4 includes the required transaction codes, quantities, prices (including weighted-average disclosure and range), and a statement that sales were pursuant to a 10b5-1 plan adopted May 2, 2025. It lists positions before/after where applicable and provides an undertaking to furnish per-trade breakdowns on request. From a governance and compliance perspective, the filing supplies the necessary elements to satisfy public disclosure obligations for these insider trades.

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).

X

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)
09/09/2025

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	09/09/2025		M		20,000	A	$60.89	77,130	D
Common Stock	09/09/2025		S		20,000(1)	D	$64.5553(2)	57,130	D
Common Stock	09/09/2025		M		1,000	A	$56.78	58,130	D
Common Stock	09/09/2025		S		1,000(1)	D	$64.5553(2)	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
Non-Qualified Stock Option (right to buy)	$56.78	09/09/2025		M			1,000	01/04/2022	01/03/2028	Common Stock	1,000	$0.0	57,203	D
Non-Qualified Stock Option (right to buy)	$60.89	09/09/2025		M			20,000	01/02/2021	01/01/2027	Common Stock	20,000	$0.0	34,461	D

Explanation of Responses:

1. Shares sold pursuant to a Rule 10b5-1 Trading Plan adopted by the reporting person on May 2, 2025.

2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $64.50 to $64.66 inclusive. The reporting person undertakes to provide to Ionis Pharmaceuticals, Inc. any security holder of Ionis Pharmaceuticals, Inc. or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnote (2) on this Form 4.

	Patrick R. O'Neil	09/10/2025
	** 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 transactions did Patrick R. O'Neil report on Form 4 for IONS?

The filer reported acquisitions of 21,000 shares via option-related entries and sales of 21,000 shares executed on 09/09/2025.

Were any sales executed under a Rule 10b5-1 plan for IONS insider activity?

Yes. The Form 4 states the shares sold were pursuant to a Rule 10b5-1 trading plan adopted May 2, 2025.

What sale price is reported for the IONS shares sold by the reporting person?

A weighted-average sale price of $64.5553 per share is reported, with transactions ranging from $64.50 to $64.66.

What option exercise prices are disclosed on the Form 4 for IONS?

The filing shows option exercise prices of $56.78 and $60.89 associated with acquisitions on 09/09/2025.

How many IONS shares does the filer beneficially own after the reported transactions?

Following the reported transactions, the filing shows beneficial ownership amounts listed as 57,130, 58,130, 77,130, and 57,203 on different line items; these reflect holdings by line item rather than a single consolidated total in the form text.

Can investors obtain per-trade prices for the sales reported on the IONS Form 4?

Yes. The reporting person undertakes to provide to Ionis Pharmaceuticals, any security holder, or the SEC staff full information regarding the number of shares sold at each separate price within the disclosed range upon request.