[Form 4] IONIS PHARMACEUTICALS INC Insider Trading Activity

Rhea-AI Filing Summary

Insider sale under 10b5-1 plan. An officer of Ionis Pharmaceuticals (IONS), Joseph T. Baroldi, sold 1,625 shares of common stock on 10/06/2025 at a weighted-average price of $69.3693 per share under a Rule 10b5-1 trading plan adopted on 05/02/2025. After the reported sale, Mr. Baroldi directly beneficially owns 30,301 shares and indirectly owns 3,071 shares through his spouse. The filer notes the sale occurred in multiple transactions at prices ranging from $69.36 to $69.41 and offers to provide a price-by-price breakdown on request.

Positive

• Sale conducted under a Rule 10b5-1 plan, indicating pre-planned, rule-compliant execution
• Reporting person retains material ownership with 30,301 direct shares and 3,071 indirect shares

Negative

• None identified as material in this filing

Insights

Corporate Governance Analyst

Routine officer sale executed under a 10b5-1 plan; ownership remains material.

The sale of 1,625 shares at a weighted-average $69.3693 per share was executed under a pre-established Rule 10b5-1 plan adopted on 05/02/2025, which provides an affirmative defense to insider trading claims when properly structured and timed.

The reporting person still holds a combined 33,372 shares (direct plus indirect), which retains a meaningful ownership stake. Investors may note the plan detail and remaining ownership when assessing insider alignment over the next 12 months.

Equity Markets Specialist

Small, disclosed sale unlikely to move market; multiple execution prices disclosed.

The transaction size (1,625 shares) is modest relative to typical free float for a public biotech and was executed across multiple trades at prices between $69.36 and $69.41. The weighted-average price is $69.3693.

Because the filer offered to provide a per-trade breakdown, market participants can obtain precise execution details on request; absent such details, treat this as a routine liquidity event under a 10b5-1 schedule within the coming quarters.

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).

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^*

Baroldi Joseph

(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, Chief Business Officer

3. Date of Earliest Transaction (Month/Day/Year)
10/06/2025

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	10/06/2025		S		1,625(1)	D	$69.3693(2)	30,301	D
Common Stock								3,071	I	by Spouse

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. 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 $69.36 to $69.41 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.

	By: Patrick R. O'Neil, attorney-in-fact For: Joseph T. Baroldi	10/08/2025
	** 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 Ionis insider Joseph T. Baroldi sell on 10/06/2025 (IONS)?

Mr. Baroldi sold 1,625 shares of Ionis common stock at a weighted-average price of $69.3693 per share under a Rule 10b5-1 plan.

How many Ionis (IONS) shares does the reporting person still own after the sale?

After the sale the reporting person directly owns 30,301 shares and indirectly owns 3,071 shares through his spouse, totaling 33,372 shares.

Was the sale by the Ionis insider part of a trading plan?

Yes. The shares were sold pursuant to a Rule 10b5-1 trading plan adopted on 05/02/2025.

At what prices were the Ionis shares sold on 10/06/2025?

The filer reports a weighted-average price of $69.3693. Individual trades ranged from $69.36 to $69.41; a per-trade breakdown is available on request.

Who filed the Form 4 for the Ionis transaction?

The Form 4 was signed by an attorney-in-fact, Patrick R. O'Neil, on behalf of Joseph T. Baroldi, with the signature date recorded as 10/08/2025.