Ionis Pharmaceuticals IONS Institutional Ownership

NASDAQ IONS

$44.27 -1.13 (-2.49%)

At close: Oct 21, 2026 · 4:00 PM EDT

Institutions by Trading Activity

515 Institutions

Increased 269 52.2%

Unchanged 86 16.7%

Reduced 160 31.1%

Ownership Statistics

13F · as of 30 Jun, 2026

Institutional Ownership

—

13F totals exceed reported shares outstanding

Shares Held by Institutions

179.76Mn

of 165.64Mn outstanding

▲+4.16% QoQ

Shares Outstanding

165.64Mn

Institutional Investors

515

filed 13F for Jun 2026

▲+20 vs prior quarter

Net Shares Added (QoQ)

+7.18Mn

accumulated since last quarter

Value of Holdings

$8.16Bn

reported market value

Shares Owned by Institutions

Shares held % of outstanding

Latest —

Average ownership —

Peak ownership —

Shares Purchased/Sold by Institutions

Accumulated Distributed

Latest quarter —

Net over range —

Accumulating quarters —

Ownership Summary

Updated Oct 11, 2026

Ionis Pharmaceuticals Inc (NASDAQ:IONS) counted 514 institutional investors among its 13F-reported shareholders for the quarter ended June 30, 2026.

Total holdings of IONS shares rose 4.16% from Q1 2026, and the holder count rose 42.78% from Q2 2025.
Of these 514 holders, 268 added to their positions, 160 reduced their stakes and 86 left their positions unchanged.
Combined, institutional investors held 179.76Mn shares of IONS as of Q2 2026, up 7.18Mn from the prior quarter and up 14.46Mn from a year earlier.
FMR LLC was the top holder of Ionis Pharmaceuticals as of June 30, 2026, with 24.63Mn shares.
Among holders that already owned Ionis Pharmaceuticals, the biggest buyers in Q2 2026 were Royal Bank of Canada (+2.38Mn shares), Barclays PLC (+1.31Mn shares), Wellington Management Group LLP (+1.26Mn shares), Alyeska Investment Group, L.P. (+944.77K shares) and Polar Capital Holdings PLC (+624.51K shares).
Among holders that kept a stake in Ionis Pharmaceuticals, the biggest sellers in Q2 2026 were T. Rowe Price Investment Management, Inc. (-2.2Mn shares), Bellevue Group AG (-846.41K shares), Millennium Management LLC (-762.63K shares), Citadel Advisors LLC (-706.25K shares) and Summit Partners Public Asset Management, LLC (-616.77K shares).
According to Business Quant data, the leading holders of IONS for Q2 2026 were FMR LLC (24.63Mn shares), Capital World Investors (21.67Mn shares), BlackRock, Inc. (10.7Mn shares), Vanguard Portfolio Management LLC (7.86Mn shares), Wellington Management Group LLP (7.65Mn shares), Vanguard Capital Management LLC (7.21Mn shares), Two Sigma Investments, LP (6.25Mn shares), Royal Bank of Canada (6.18Mn shares), State Street Corp (4.33Mn shares) and T. Rowe Price Investment Management, Inc. (3.96Mn shares).

Form 13F Holdings

515 Institutional Holders

Report period 30 Jun, 2026

Total shares held 179.76Mn

Of outstanding —

#	Institution	CIK	Shares Held	% of Outstanding	Change (QoQ)	Change (%)	Value (USD)
1	FMR LLC	0000315066	24,631,956	14.87%	▲75,319	+0.31%	$1.95Bn
2	Capital World Investors	0001422849	21,669,226	13.08%	▲482,857	+2.28%	$1.72Bn
3	BlackRock, Inc.	0002012383	10,704,660	6.46%	▲262,184	+2.51%	$848.77Mn
4	VANGUARD PORTFOLIO MANAGEMENT LLC	0002100121	7,859,529	4.75%	▲50,627	+0.65%	$623.18Mn
5	WELLINGTON MANAGEMENT GROUP LLP	0000902219	7,651,415	4.62%	▲1,259,599	+19.71%	$606.68Mn
6	VANGUARD CAPITAL MANAGEMENT LLC	0002100119	7,211,497	4.35%	▲93,167	+1.31%	$571.80Mn
7	TWO SIGMA INVESTMENTS, LP	0001179392	6,252,342	3.77%	▲394,713	+6.74%	$495.75Mn
8	Royal Bank Of Canada	0001000275	6,182,479	3.73%	▲2,380,664	+62.62%	$490.21Mn
9	State Street Corp	0000093751	4,334,848	2.62%	▲339,284	+8.49%	$343.71Mn
10	T. Rowe Price Investment Management, Inc.	0001897612	3,959,372	2.39%	▼2,199,655	-35.71%	$313.94K
11	GEODE CAPITAL MANAGEMENT, LLC	0001214717	3,584,024	2.16%	▼400,308	-10.05%	$294.75Mn
12	PRICE T ROWE ASSOCIATES INC /MD/	0000080255	3,184,500	1.92%	▲159,249	+5.26%	$252.50K
13	Jpmorgan Chase & Co	0000019617	2,671,717	1.61%	▲308,150	+13.04%	$216.20Mn
14	Artisan Partners Limited Partnership	0001466153	2,640,024	1.59%	▲581,716	+28.26%	$209.33Mn
15	Tweedy, Browne Co LLC	0000732905	2,280,311	1.38%	▲4,686	+0.21%	$180.81Mn
16	Deep Track Capital, LP	0001856083	2,200,000	1.33%	▲250,000	+12.82%	$174.44Mn
17	Goldman Sachs Group Inc	0000886982	2,109,945	1.27%	▲410,098	+24.13%	$167.30Mn
18	BAKER BROS. ADVISORS LP	0001263508	2,047,727	1.24%	0	0.00%	$162.36Mn
19	DEERFIELD MANAGEMENT COMPANY, L.P.	0001009258	1,979,669	1.20%	0	0.00%	$156.97Mn
20	AMERICAN CENTURY COMPANIES INC	0000748054	1,947,076	1.18%	▲283,273	+17.03%	$154.38Mn

Showing 1 to 20 of 515 holders