Why Ionis Pharmaceuticals (IONS) Stock Is Down Today

Ionis Pharmaceuticals (IONS) is down 7.6% today. Here is some analysis on what might have caused this price movement.

Analysis: The most likely driver is continued fallout from the recent Phase 3 failure of pelacarsen, a major partnered cardiovascular program that had been part of the company’s long-term value story. Today’s selling also appears to reflect follow-through from analyst target cuts and reduced expectations for future milestone and royalty contributions tied to that asset. ([sec.gov](https://www.sec.gov/Archives/edgar/data/874015/000114036126035802/ef20081690_8k.htm?utm_source=openai))

Details:

On September 4, 2026, Ionis disclosed in an 8-K that partner Novartis said pelacarsen did not meet the primary endpoint in the Phase 3 Lp(a)HORIZON cardiovascular outcomes study. ([sec.gov](https://www.sec.gov/Archives/edgar/data/874015/000114036126035802/ef20081690_8k.htm?utm_source=openai))

That outcome matters because pelacarsen was one of Ionis’ important partnered late-stage programs, so the miss likely lowered investor expectations for future economics from the drug. This is an inference based on the company disclosure and subsequent analyst model changes. ([sec.gov](https://www.sec.gov/Archives/edgar/data/874015/000114036126035802/ef20081690_8k.htm?utm_source=openai))

Several analysts cut price targets shortly after the trial result, including reductions noted on September 8, 2026, which likely added pressure to the shares. ([benzinga.com](https://www.benzinga.com/quote/ions/price-targets?utm_source=openai))

Ionis also recently announced FDA approval of Zanvastro for Alexander disease, but the market appears to be focusing more heavily on the pelacarsen setback than on that positive regulatory event. ([ir.ionis.com](https://ir.ionis.com/investor-news/press-releases?utm_source=openai))

Sources:

Ionis Pharmaceuticals, SEC, Benzinga, TipRanks

Disclaimer: This price movement analysis was generated with the help of AI. Please double-check the information provided for mistakes.

$IONS Insider Trading Activity

$IONS insiders have traded $IONS stock on the open market 36 times in the past 6 months. Of those trades, 2 have been purchases and 34 have been sales.

Here’s a breakdown of recent trading of $IONS stock by insiders over the last 6 months:

BRETT P MONIA (Chief Executive Officer) has made 0 purchases and 5 sales selling 90,173 shares for an estimated $7,181,536.
JOSEPH LOSCALZO has made 0 purchases and 2 sales selling 77,289 shares for an estimated $5,801,226.
HOLLY B. KORDASIEWICZ (EVP, Chief Development Officer) has made 0 purchases and 3 sales selling 61,208 shares for an estimated $4,496,944.
JOSEPH III KLEIN has made 0 purchases and 6 sales selling 43,950 shares for an estimated $3,339,956.
EUGENE SCHNEIDER (EVP, Chf Clinical Develop Ofcr) has made 0 purchases and 2 sales selling 31,812 shares for an estimated $2,519,682.
C FRANK BENNETT (EVP, Chief Scientific Officer) has made 0 purchases and 2 sales selling 20,536 shares for an estimated $1,744,623.
SPENCER R BERTHELSEN has made 0 purchases and 2 sales selling 16,000 shares for an estimated $1,193,280.
MICHAEL R HAYDEN has made 2 purchases buying 20,000 shares for an estimated $1,058,700 and 0 sales.
JOSEPH BAROLDI (EVP, Chief Business Officer) has made 0 purchases and 3 sales selling 12,880 shares for an estimated $987,378.
ALLENE M. DIAZ sold 10,111 shares for an estimated $863,637
ERIC SWAYZE (EVP Research) sold 10,602 shares for an estimated $839,491
ELIZABETH L HOUGEN (EVP, Finance & CFO) sold 10,172 shares for an estimated $744,661
SHANNON L. DEVERS (EVP, Chief Human Resources Ofc) sold 6,193 shares for an estimated $458,613
B LYNNE PARSHALL has made 0 purchases and 2 sales selling 5,000 shares for an estimated $381,366.
KYLE JENNE (EVP, Chf GL Pdt Str Ofcr) sold 4,902 shares for an estimated $368,488
PATRICK R. O'NEIL (EVP CLO & General Counsel) sold 3,069 shares for an estimated $245,520
BRIAN BIRCHLER (EVP, Corp and Development Ops) sold 973 shares for an estimated $73,015

To track insider transactions, check out Quiver Quantitative's insider trading dashboard. You can access data on insider stock transactions through the Quiver Quantitative API insider transaction endpoint.

$IONS Hedge Fund Activity

We have seen 261 institutional investors add shares of $IONS stock to their portfolio, and 256 decrease their positions in their most recent quarter.

Here are some of the largest recent moves:

JPMORGAN CHASE & CO added 2,671,717 shares (+inf%) to their portfolio in Q2 2026, for an estimated $211,840,440
ROYAL BANK OF CANADA added 2,380,664 shares (+62.6%) to their portfolio in Q2 2026, for an estimated $188,762,848
T. ROWE PRICE INVESTMENT MANAGEMENT, INC. removed 1,830,491 shares (-31.6%) from their portfolio in Q2 2026, for an estimated $145,139,631
SIXTH STREET PARTNERS MANAGEMENT COMPANY, L.P. added 1,605,054 shares (+inf%) to their portfolio in Q2 2026, for an estimated $127,264,731
BARCLAYS PLC added 1,313,262 shares (+453.0%) to their portfolio in Q2 2026, for an estimated $104,128,543
WELLINGTON MANAGEMENT GROUP LLP added 1,259,599 shares (+19.7%) to their portfolio in Q2 2026, for an estimated $99,873,604
CITADEL ADVISORS LLC removed 1,192,102 shares (-55.8%) from their portfolio in Q1 2026, for an estimated $89,514,939

To track hedge funds' stock portfolios, check out Quiver Quantitative's institutional holdings dashboard. You can access data on hedge funds moves and 13F filings through the Quiver Quantitative API 13F endpoint.

$IONS Analyst Ratings

Wall Street analysts have issued reports on $IONS in the last several months. We have seen 1 firms issue buy ratings on the stock, and 0 firms issue sell ratings.

Here are some recent analyst ratings:

Barclays issued a "Overweight" rating on 04/30/2026

To track analyst ratings and price targets for $IONS, check out Quiver Quantitative's $IONS forecast page.

$IONS Price Targets

Multiple analysts have issued price targets for $IONS recently. We have seen 12 analysts offer price targets for $IONS in the last 6 months, with a median target of $110.5.

Here are some recent targets:

Joseph Stringer from Needham set a target price of $86.0 on 07/09/2026
Akash Tewari from Jefferies set a target price of $90.0 on 07/09/2026
Mitchell S. Kapoor from HC Wainwright & Co. set a target price of $130.0 on 06/25/2026
Mani Foroohar from Leerink Partners set a target price of $129.0 on 06/25/2026
Salveen Richter from Goldman Sachs set a target price of $75.0 on 06/25/2026
Yaron Werber from TD Cowen set a target price of $108.0 on 06/15/2026
Eric Joseph from Citigroup set a target price of $115.0 on 05/19/2026

This article is not financial advice. See Quiver Quantitative's disclaimers for more information. Note that there may be inaccuracies due to mistakes in ticker-mapping, and other anomalies.