Joseph T. Baroldi - 02 Oct 2025 Form 4 Insider Report for IONIS PHARMACEUTICALS INC (IONS)

Role: EVP, Chief Business Officer
Signature: By: Patrick R. O'Neil, attorney-in-fact For: Joseph T. Baroldi
Issuer symbol: IONS
Transactions as of: 02 Oct 2025
Net transactions value: -$543,210
Form type: 4
Filing time: 02 Oct 2025, 19:35:51 UTC
Previous filing: 11 Sep 2025
Next filing: 08 Oct 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Baroldi Joseph	EVP, Chief Business Officer	2855 GAZELLE COURT, CARLSBAD	By: Patrick R. O'Neil, attorney-in-fact For: Joseph T. Baroldi	02 Oct 2025	0001813775

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	IONS	Common Stock	Options Exercise	$477,000	+15,000	+47%	$31.80	46,926	02 Oct 2025	Direct
transaction	IONS	Common Stock	Sale	$1,020,210	-15,000	-32%	$68.01	31,926	02 Oct 2025	Direct	F1, F2
holding	IONS	Common Stock						3,071	02 Oct 2025	by Spouse

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	IONS	Non-Qualified Stock Option (right to buy)	Options Exercise	$0	-15,000	-36%	$0.000000	26,700	02 Oct 2025	Common Stock	15,000	$31.80	Direct

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.

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).

Explanation of Responses:

Id	Content
F1	Shares sold pursuant to a Rule 10b5-1 Trading Plan adopted by the reporting person on May 2, 2025.
F2	The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $68.00 to $68.07 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.

Content

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

The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $68.00 to $68.07 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.