Ionis Pharmaceuticals Inc (IONS) Institutional Ownership

Institutions by Trading Activity

Ownership Statistics

159,765,000Shares Outstanding

174,537,556Shares held by institutions

$13,133,951,089Value of institutional holdings

109.25%Institutional ownership %

5.83%Shares Changed QoQ

480No. of institutional investors

Shares Owned by Institutions

Shares Purchased/Sold by Institutions

Ownership Summary

Ionis Pharmaceuticals Inc (NASDAQ:IONS) has 480 institutional investors that have filed 13F reports for the period ending December 2025.

These investors held 108.7% of outstanding shares in December 2025, down from 126.6% in September 2025.
They increased total shares held in IONS by 6.15% quarter over quarter, and investors in Ionis Pharmaceuticals increased 38.33% from a year ago.
Of these 480 holders, 269 added to their stakes in Ionis Pharmaceuticals, 142 trimmed positions, and 69 made no changes.
In total, institutional investors 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.
Aspect Partners, LLC is the top holder of Ionis Pharmaceuticals as of December 31, 2025, with 20 shares representing 0.0% of outstanding stock.
According to Business Quant data, leading holders of IONS for December 2025 are Aspect Partners, LLC (20).

480 Institutional Holders

174,537,556 Total Shares Held

Rows:

Download Data

Owner Name	Date	Shares Held	Change (QoQ)	Change (%)	Value (USD)
FMR LLC	31 Dec, 2025	24,072,101	383,063	1.62%	$1,904,343,910.00
Capital World Investors	31 Dec, 2025	17,961,299	5,238,571	41.17%	$1,420,918,364.00
VANGUARD GROUP INC	31 Dec, 2025	16,440,459	-41,271	-0.25%	$1,300,604,712.00
T. Rowe Price Investment Management, Inc.	31 Dec, 2025	14,897,882	1,740,953	13.23%	$1,178,573.00
BlackRock, Inc.	31 Dec, 2025	10,647,863	199,923	1.91%	$842,352,443.00
WELLINGTON MANAGEMENT GROUP LLP	31 Dec, 2025	6,260,325	-328,486	-4.99%	$495,254,312.00
Bellevue Group AG	31 Dec, 2025	4,802,199	-1,442,252	-23.10%	$379,901,963.00
State Street Corp	31 Dec, 2025	3,974,865	-413,786	-9.43%	$314,451,570.00
GEODE CAPITAL MANAGEMENT, LLC	31 Dec, 2025	3,148,849	82,560	2.69%	$249,157,703.00
TWO SIGMA ADVISERS, LP	31 Dec, 2025	3,052,111	979,000	47.22%	$241,452,501.00
TWO SIGMA INVESTMENTS, LP	31 Dec, 2025	2,658,646	1,082,703	68.70%	$210,325,485.00
Tweedy, Browne Co LLC	31 Dec, 2025	2,464,930	-436,286	-15.04%	$195,000,612.00
Jpmorgan Chase & Co	31 Dec, 2025	2,304,792	1,215,856	111.66%	$182,332,112.00
CITADEL ADVISORS LLC	31 Dec, 2025	2,134,636	-267,429	-11.13%	$168,871,054.00
DEERFIELD MANAGEMENT COMPANY, L.P.	31 Dec, 2025	1,979,669	0	0.00%	$156,611,615.00
BAKER BROS. ADVISORS LP	31 Dec, 2025	1,791,841	1,225,043	216.13%	$141,752,542.00
Goldman Sachs Group Inc	31 Dec, 2025	1,711,932	934,362	120.16%	$135,430,940.00
Deep Track Capital, LP	31 Dec, 2025	1,700,000	-2,108,144	-55.36%	$134,487,000.00
AMERICAN CENTURY COMPANIES INC	31 Dec, 2025	1,617,106	244,881	17.85%	$127,929,439.00
CHARLES SCHWAB INVESTMENT MANAGEMENT INC	31 Dec, 2025	1,541,841	21,890	1.44%	$121,975,042.00

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