Ticker · CUSIP 462222100

IONS

IONIS PHARMACEUTICALS INC

Healthcare·Biotechnology

···Share

Holders (tracked)

Combined shares

15,908,591

Combined value

$1.26B

Last close

$75.71

Quarter

2025Q4

Price is -4.3% vs the avg quarter-end implied price across tracked holders.

Price · 1Y$75.71+47.31 (+166.58%)H $86.50 · L $28.40 · Avg Vol 2.2M

Tracked holders · last 8 quarters

+4 vs previous quarter over the last 8.

SEC event timeline

29 events

Paul Tudor Jones (Tudor Investment) opened position2026-02-17
+3,661 shares · 2025Q4
Position
AQR Capital Management added2026-02-17
+11,947 shares · 2025Q4
Position
Ken Griffin (Citadel Advisors) trimmed2026-02-17
−267,429 shares · 2025Q4
Position
D.E. Shaw & Co. trimmed2026-02-17
−298,135 shares · 2025Q4
Position
Two Sigma Investments added2026-02-17
+1,082,703 shares · 2025Q4
Position
Ron Baron (Baron Capital / BAMCO) added2026-02-17
+11,000 shares · 2025Q4
Position
Izzy Englander (Millennium Mgmt) trimmed2026-02-17
−686,308 shares · 2025Q4
Position
Steve Cohen (Point72) opened position2026-02-17
+28,200 shares · 2025Q4
Position
T. Rowe Price added2026-02-17
+258,155 shares · 2025Q4
Position
Wellington Management trimmed2026-02-17
−328,486 shares · 2025Q4
Position
Ray Dalio (Bridgewater Associates) added2026-02-13
+24,128 shares · 2025Q4
Position
Renaissance Technologies trimmed2026-02-12
−263,107 shares · 2025Q4
Position
Cathie Wood (ARK Invest) trimmed2026-02-11
−208,247 shares · 2025Q4
Position
Norges Bank (Norway SWF) opened position2026-02-10
+320,160 shares · 2025Q4
Position
Ken Fisher (Fisher Asset Mgmt) added2026-02-09
+135,405 shares · 2025Q4
Position
D.E. Shaw & Co. opened position2025-11-14
+630,938 shares · 2025Q3
Position
AQR Capital Management opened position2025-11-14
+6,815 shares · 2025Q3
Position
Izzy Englander (Millennium Mgmt) trimmed2025-11-14
−1,869,957 shares · 2025Q3
Position
Steve Cohen (Point72) exited2025-11-14
−292,647 shares · 2025Q3
Position
Two Sigma Investments trimmed2025-11-14
−212,424 shares · 2025Q3
Position
T. Rowe Price trimmed2025-11-14
−396,388 shares · 2025Q3
Position
Wellington Management added2025-11-14
+243,035 shares · 2025Q3
Position
Ron Baron (Baron Capital / BAMCO) opened position2025-11-14
+25,000 shares · 2025Q3
Position
Ray Dalio (Bridgewater Associates) opened position2025-11-13
+43,578 shares · 2025Q3
Position
Renaissance Technologies added2025-11-13
+216,000 shares · 2025Q3
Position
Norges Bank (Norway SWF) exited2025-11-13
−450,254 shares · 2025Q3
Position
Ken Fisher (Fisher Asset Mgmt) opened position2025-11-12
+6,210 shares · 2025Q3
Position
Norges Bank (Norway SWF) added2025-11-12
+1,007,820 shares · 2024Q3
Position
Cathie Wood (ARK Invest) trimmed2025-11-12
−269,103 shares · 2025Q3
Position

Insider activity

No insider transactions in the last 30 days.

View full insider history for IONS →

Follow-the-investor returns

If you'd copied each holder of IONS…

Cost basis inferred from each manager's quarter-over-quarter position changes. Sorted by % return on the position they're still holding.

Investor	First in	Cost basis	Return	Position value today
Paul Tudor Jones (Tudor Investment)	2016Q2	$35.07	+115.9%	$277K
Steve Cohen (Point72)	2016Q1	$39.14	+93.4%	$1.1M
Steve Cohen (Point72)	2016Q1	$39.14	+93.4%	$1.1M
Izzy Englander (Millennium Mgmt)	2016Q1	$39.33	+92.5%	$7.1M
Wellington Management	2016Q1	$43.55	+73.8%	$474.0M
Cathie Wood (ARK Invest)	2016Q4	$45.67	+65.8%	$32.0M
Renaissance Technologies	2016Q1	$51.84	+46.0%	$16.9M
T. Rowe Price	2016Q1	$52.64	+43.8%	$226.2M
Two Sigma Investments	2017Q2	$55.09	+37.4%	$201.3M
D.E. Shaw & Co.	2016Q1	$64.57	+17.3%	$25.2M
Ray Dalio (Bridgewater Associates)	2021Q2	$66.50	+13.9%	$5.1M
Ron Baron (Baron Capital / BAMCO)	2025Q3	$69.60	+8.8%	$2.7M
AQR Capital Management	2016Q1	$70.55	+7.3%	$1.4M
Ken Griffin (Citadel Advisors)	2016Q1	$78.38	-3.4%	$5.2M
Ken Griffin (Citadel Advisors)	2016Q1	$78.38	-3.4%	$5.2M
Ken Griffin (Citadel Advisors)	2016Q1	$78.38	-3.4%	$5.2M
Ken Fisher (Fisher Asset Mgmt)	2025Q3	$78.51	-3.6%	$10.7M
Norges Bank (Norway SWF)	2016Q1	$3949.51	-98.1%	$24.2M

Who moved on this name in 2025Q4

Position changes reported for the latest quarter, grouped by direction.

New positions3

Norges Bank (Norway SWF)
+320,160
$25.3M
Steve Cohen (Point72)
+28,200
$2.2M
Paul Tudor Jones (Tudor Investment)
+3,661
$290K

Added to6

Two Sigma Investments
+1,082,703
$85.7M
Ken Fisher (Fisher Asset Mgmt)
+135,405
$10.7M
Ray Dalio (Bridgewater Associates)
+24,128
$1.9M
AQR Capital Management
+11,947
$941K
Ron Baron (Baron Capital / BAMCO)
+11,000
$870K
T. Rowe Price
+258,155
$20K

Trimmed6

Izzy Englander (Millennium Mgmt)
−686,308
$54.3M
Wellington Management
−328,486
$26.0M
D.E. Shaw & Co.
−298,135
$23.6M
Ken Griffin (Citadel Advisors)
−267,429
$21.2M
Renaissance Technologies
−263,107
$20.8M
Cathie Wood (ARK Invest)
−208,247
$16.5M

Exited0

—

Institutional ownership over time

Distinct super-investors holding this ticker · combined dollar value, by quarter.

Quarter	Holders	Shares	Combined value	Δ holders
2022Q1	13	32,551,746	$30.27B	—
2022Q2	15	32,288,669	$42.55B	+2
2022Q3	14	20,869,327	$923.1M	-1
2022Q4	15	19,978,459	$754.6M	+1
2023Q1	14	18,177,132	$649.7M	-1
2023Q2	15	19,885,060	$815.9M	+1
2023Q3	13	18,974,289	$860.7M	-2
2023Q4	13	19,784,094	$1.00B	—
2024Q1	13	24,309,530	$1.05B	—
2024Q2	15	26,039,162	$1.24B	+2
2024Q3	13	18,633,505	$746.5M	-2
2024Q4	12	10,771,868	$376.6M	-1
2025Q1	12	19,084,185	$575.8M	—
2025Q2	12	17,473,657	$690.4M	—
2025Q3	14	16,092,444	$1.05B	+2
2025Q4	18	15,908,591	$1.26B	+4

Who owns IONS

18 super-investors · 2025Q4

Tracked stake

15.91M

Combined value

$1.26B

% of shares outstanding

—

shares-out unknown

Quarter action mix

New4Added6Trim8

#	Manager	Shares	Value	% of book	Last action
1	Wellington Management	6.26M	$495M	0.1%	Trim−328.5K
2	T. Rowe Price	2.99M	$236M	0.0%	Added+258.2K
3	Two Sigma Investments	2.66M	$210M	0.3%	Added+1.08M
4	Ken Griffin Citadel Advisors	2.13M	$169M	0.0%	Trim−267.4K
5	Cathie Wood ARK Invest	423.0K	$33M	0.2%	Trim−208.2K
6	D.E. Shaw & Co.	332.8K	$26M	0.0%	Trim−298.1K
7	Norges Bank Norway SWF	320.2K	$25M	0.0%	New+320.2K
8	Renaissance Technologies	223.6K	$18M	0.0%	Trim−263.1K
9	Ken Fisher Fisher Asset Mgmt	141.6K	$11M	0.0%	Added+135.4K
10	Ken Griffin Citadel Advisors	109.4K	$9M	0.0%	Trim−267.4K
11	Izzy Englander Millennium Mgmt	93.3K	$7M	0.0%	Trim−686.3K
12	Ken Griffin Citadel Advisors	69.0K	$5M	0.0%	Trim−267.4K
13	Ray Dalio Bridgewater Associates	67.7K	$5M	0.0%	Added+24.1K
14	Ron Baron Baron Capital / BAMCO	36.0K	$3M	0.0%	Added+11.0K
15	AQR Capital Management	18.8K	$1M	0.0%	Added+11.9K
16	Steve Cohen Point72	14.1K	$1M	0.0%	New+28.2K
17	Steve Cohen Point72	14.1K	$1M	0.0%	New+28.2K
18	Paul Tudor Jones Tudor Investment	3.7K	$290K	0.0%	New+3.7K

Recent moves

20 transactions

TRIMKen Griffin (Citadel Advisors)
−267,429 · 2025Q4
NEWPaul Tudor Jones (Tudor Investment)
+3,661 · 2025Q4
ADDRon Baron (Baron Capital / BAMCO)
+11,000 · 2025Q4
TRIMD.E. Shaw & Co.
−298,135 · 2025Q4
TRIMIzzy Englander (Millennium Mgmt)
−686,308 · 2025Q4
ADDAQR Capital Management
+11,947 · 2025Q4
NEWSteve Cohen (Point72)
+28,200 · 2025Q4
ADDT. Rowe Price
+258,155 · 2025Q4
ADDTwo Sigma Investments
+1,082,703 · 2025Q4
TRIMWellington Management
−328,486 · 2025Q4
ADDRay Dalio (Bridgewater Associates)
+24,128 · 2025Q4
TRIMRenaissance Technologies
−263,107 · 2025Q4
TRIMCathie Wood (ARK Invest)
−208,247 · 2025Q4
NEWNorges Bank (Norway SWF)
+320,160 · 2025Q4
ADDKen Fisher (Fisher Asset Mgmt)
+135,405 · 2025Q4
TRIMIzzy Englander (Millennium Mgmt)
−1,869,957 · 2025Q3
SOLDSteve Cohen (Point72)
−292,647 · 2025Q3
TRIMTwo Sigma Investments
−212,424 · 2025Q3
NEWD.E. Shaw & Co.
+630,938 · 2025Q3
TRIMT. Rowe Price
−396,388 · 2025Q3

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