Ionis Pharmaceuticals Inc (IONS) Institutional Ownership

Institutions by Trading Activity

Ownership Statistics

0Shares Outstanding

11,010,190Shares held by institutions

$798,348,877Value of institutional holdings

93.39%Institutional ownership %

4.20%Shares Changed QoQ

362No. of institutional investors

Shares Owned by Institutions

Shares Purchased/Sold by Institutions

Ownership Summary

Ionis Pharmaceuticals Inc (NASDAQ:IONS) showed up in the 13F filings of 480 institutional investors as of December 2025.

Collectively, these holders controlled 108.7% of Ionis Pharmaceuticals's outstanding shares in December 2025, down from 126.6% in September 2025.
Their total shares held in IONS increased 6.15% from the prior quarter, while the number of investors in Ionis Pharmaceuticals increased 38.33% year over year.
Activity in IONS broke down as 269 buyers, 142 sellers, and 69 unchanged among 480 total holders.
Institutional investors collectively held 173.62Mn shares in Ionis Pharmaceuticals as of December 2025, up by 10.05Mn shares quarter on quarter, and up 11.41Mn shares year over year.
As of December 31, 2025, the biggest holder of Ionis Pharmaceuticals is FMR LLC at 24.07Mn shares, representing 15.07% of shares outstanding.
Leading buyers of Ionis Pharmaceuticals shares for the quarter ending December 2025 were Capital World Investors (5.24Mn), T. Rowe Price Investment Management, Inc. (1.74Mn), Franklin Resources Inc (1.31Mn), BAKER BROS. ADVISORS LP (1.23Mn), Jpmorgan Chase & Co (1.22Mn).
The largest sellers of Ionis Pharmaceuticals for the quarter ending December 2025 were Deep Track Capital, LP (2.11Mn), Bellevue Group AG (1.44Mn), ADAGE CAPITAL PARTNERS GP, L.L.C. (1.18Mn), Bank Of America Corp /De/ (927.01K), Bank Of Montreal /Can/ (711.04K).
According to Business Quant data, leading holders of IONS for December 2025 are FMR LLC (24.07Mn), Capital World Investors (17.96Mn), VANGUARD GROUP INC (16.44Mn), T. Rowe Price Investment Management, Inc. (14.9Mn), BlackRock, Inc. (10.65Mn), WELLINGTON MANAGEMENT GROUP LLP (6.26Mn), Bellevue Group AG (4.8Mn), State Street Corp (3.97Mn), GEODE CAPITAL MANAGEMENT, LLC (3.15Mn), TWO SIGMA ADVISERS, LP (3.05Mn).

480 Institutional Holders

11,010,190 Total Shares Held

Rows:

Download Data

Owner Name	Date	Change (QoQ)	Change (%)	Value (USD)
BlackRock, Inc.	31 Dec, 2025	199,923	1.91%	$0.00
FMR LLC	31 Dec, 2025	383,063	1.62%	$0.00
T. Rowe Price Investment Management, Inc.	31 Dec, 2025	1,740,953	13.23%	$0.00
Barclays Plc	31 Dec, 2025	-508,209	-37.62%	$0.00
Capital World Investors	31 Dec, 2025	5,238,571	41.17%	$0.00
Bellevue Group AG	31 Dec, 2025	-1,442,252	-23.10%	$0.00
PEAK6 LLC	31 Dec, 2025	55,172	902.68%	$0.00
VANGUARD GROUP INC	31 Dec, 2025	-41,271	-0.25%	$0.00
Deep Track Capital, LP	31 Dec, 2025	-2,108,144	-55.36%	$0.00
HSBC HOLDINGS PLC	31 Dec, 2025	8,426	18.54%	$0.00
WELLINGTON MANAGEMENT GROUP LLP	31 Dec, 2025	-328,486	-4.99%	$0.00
SUMMIT PARTNERS PUBLIC ASSET MANAGEMENT, LLC	31 Dec, 2025	712,706	95.03%	$0.00
Rockefeller Capital Management L.P.	31 Dec, 2025	3,249	147.48%	$0.00
State Street Corp	31 Dec, 2025	-413,786	-9.43%	$0.00
Pictet Asset Management Holding SA	31 Dec, 2025	25,367	1.82%	$0.00
GEODE CAPITAL MANAGEMENT, LLC	31 Dec, 2025	82,560	2.69%	$0.00
Polar Capital Holdings Plc	31 Dec, 2025	299,802	29.00%	$0.00
TWO SIGMA ADVISERS, LP	31 Dec, 2025	979,000	47.22%	$0.00
UBS Group AG	31 Dec, 2025	-1,949	-0.19%	$0.00
TWO SIGMA INVESTMENTS, LP	31 Dec, 2025	1,082,703	68.70%	$0.00

1 - 20 of 480

Research Tools