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

Rhea-AI Filing Summary

Insider sale reported by Director B. Lynne Parshall of Ionis Pharmaceuticals (IONS). On 09/02/2025 the reporting person sold a total of 20,000 shares of Ionis common stock in two transactions executed under a Rule 10b5-1 trading plan adopted May 6, 2025. The first block of 10,750 shares was sold at a weighted-average price of $50.42 (individual trades ranged $50.0137–$50.92) leaving 75,594 shares beneficially owned after the sale. The second block of 9,250 shares was sold at a weighted-average price of $51.49 (individual trades ranged $51.24–$51.81) leaving 66,344 shares beneficially owned after that sale. The Form 4 was signed by an attorney-in-fact on 09/04/2025.

Positive

• Sales executed under a Rule 10b5-1 trading plan, indicating pre-established execution and potential compliance with insider trading rules
• Weighted-average prices and execution ranges disclosed, providing transparent pricing information for the transactions

Negative

• Director reduced holdings by 20,000 shares (10,750 and 9,250), which may be perceived negatively by some investors
• Form shows reduced beneficial ownership totals (75,594 and 66,344 shares remaining after respective sales)

Insights

Securities Analyst

TL;DR: Director sold 20,000 IONS shares under a pre-established 10b5-1 plan; sales were executed at roughly $50–$51.5.

The Form 4 discloses non-derivative dispositions totaling 20,000 shares on a single day under a Rule 10b5-1 plan adopted May 6, 2025. Weighted-average prices and reported ranges are provided for both blocks, which increases transparency about execution. The filing shows remaining direct beneficial ownership figures after each transaction, allowing investors to track the director's residual stake. No additional material disclosures (e.g., options, grants, or other related-party transactions) are included.

Corporate Governance Expert

TL;DR: Transaction appears procedural and compliant; executed under a documented 10b5-1 trading plan.

The reporting person is identified as a director and the sales are explicitly noted as executed pursuant to an established 10b5-1 plan, which typically reduces questions about opportunistic timing. The Form 4 includes weighted-average prices and commits to provide detailed breakdowns on request, which supports disclosure completeness. The filing does not disclose any amendments, derivative activity, or other governance actions tied to these sales.

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^*

PARSHALL B LYNNE

(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)

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

3. Date of Earliest Transaction (Month/Day/Year)
09/02/2025

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	09/02/2025		S		10,750(1)	D	$50.42(2)	75,594	D
Common Stock	09/02/2025		S		9,250(1)	D	$51.49(3)	66,344	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. Shares sold pursuant to a Rule 10b5-1 Trading Plan adopted by the reporting person on May 6, 2025.

2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $50.0137 to $50.92 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.

3. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $51.24 to $51.81 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 (3) on this Form 4.

	By: Patrick R. O'Neil, attorney-in-fact For: B. Lynne Parshall	09/04/2025
	** 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 B. Lynne Parshall report on Form 4 for IONS?

The Form 4 reports the sale of 20,000 shares of Ionis common stock in two blocks on 09/02/2025, executed under a Rule 10b5-1 trading plan.

At what prices were the IONS shares sold?

The first block of 10,750 shares had a weighted-average price of $50.42 (range $50.0137–$50.92). The second block of 9,250 shares had a weighted-average price of $51.49 (range $51.24–$51.81).

How many IONS shares does the reporting person own after the sales?

The filing reports 75,594 shares and 66,344 shares as the amounts beneficially owned following each reported transaction.

Was the sale part of an approved trading plan?

Yes. The sales were made pursuant to a Rule 10b5-1 trading plan adopted on May 6, 2025, as stated in the Form 4.

Who signed the Form 4 filing?

The Form 4 was executed by Patrick R. O'Neil, attorney-in-fact on behalf of B. Lynne Parshall on 09/04/2025.