CSS LLC’s Ionis Pharmaceuticals IONS Stock Holding History

CSS LLC’s Portfolio IONS Stock Details IONS Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q2	$12.1M	Buy	152,289 +73,196	+93%	+$5.51M	0.47%	35
2026 Q1	$5.94M	Buy	+79,093	New	+$6.24M	0.28%	65
2021 Q2	–	Sell	-9,605	Closed	-$432K	–	1127
2021 Q1	$432K	Buy	+9,605	New	+$536K	0.02%	610
2020 Q1	–	Sell	-98,235	Closed	-$5.48M	–	695
2019 Q4	$5.93M	Buy	98,235 +89,646	+1,044%	+$5.34M	0.33%	67
2019 Q3	$515K	Buy	8,589 +6,066	+240%	+$395K	0.03%	306
2019 Q2	$162K	Buy	+2,523	New	+$178K	0.01%	480
2018 Q4	–	Sell	-7,136	Closed	-$364K	–	554
2018 Q3	$368K	Buy	7,136 +3,236	+83%	+$152K	0.02%	345
2018 Q2	$163K	Buy	+3,900	New	+$173K	0.01%	432
2017 Q4	–	Sell	-11,937	Closed	-$655K	–	637
2017 Q3	$605K	Buy	+11,937	New	+$625K	0.03%	321
2017 Q2	–	Sell	-10,232	Closed	-$411K	–	664
2017 Q1	$411K	Buy	+10,232	New	+$460K	0.02%	362
2015 Q2	–	Sell	-17,824	Closed	-$1.13M	–	764
2015 Q1	$1.14M	Buy	+17,824	New	+$1.21M	0.06%	271

Other funds holding IONS

Fidelity Investments Boston, Massachusetts $2.3T AUM 54.33% 1-Year Est. Return

Capital World Investors Los Angeles, California $846B AUM 46.74% 1-Year Est. Return

BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return

Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM

Wellington Management Group Boston, Massachusetts $580B AUM 38.23% 1-Year Est. Return

Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM

Two Sigma Investments New York $138B AUM 41.87% 1-Year Est. Return

Royal Bank of Canada Toronto, Ontario, Canada $672B AUM 33.48% 1-Year Est. Return

State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return

T. Rowe Price Investment Management Baltimore, Maryland $153B AUM 38.14% 1-Year Est. Return

CSS LLC's IONS Position: Q2 2026 in Review

CSS LLC increased its Ionis Pharmaceuticals (IONS) stake by 93% in Q2 2026, buying an estimated $5.51M and bringing the position to 152,289 shares worth $12.1M. The position accounts for 0.47% of the portfolio, ranked #35.

CSS LLC first reported a position in IONS in Q1 2015 and has held it in 11 quarters since. 514 funds tracked by Wall St. Rank hold IONS as of Q2 2026.

CSS LLC held 152,289 shares of Ionis Pharmaceuticals worth $12.1M as of Q2 2026.
CSS LLC bought 73,196 Ionis Pharmaceuticals shares in Q2 2026, an estimated $5.51M.
Ionis Pharmaceuticals made up 0.47% of CSS LLC's portfolio in Q2 2026, its #35 holding.
CSS LLC first reported a position in Ionis Pharmaceuticals in Q1 2015 and has held it in 11 quarters since.
514 funds tracked by Wall St. Rank held Ionis Pharmaceuticals as of Q2 2026.

Based on CSS LLC's 13F filing for Q2 2026, filed 14 Aug 2026.