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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
2025
Q4 		– Sell
-4,000
Closed -$262K – 1129
2025
Q3 		$262K Buy
+4,000
New +$195K 0.01% 705
2020
Q1 		– Sell
-15,000
Closed -$906K – 694
2019
Q4 		$906K Hold
15,000
– – 0.05% 267
2019
Q3 		$899K Buy
15,000
+9,000
+150% +$587K 0.06% 236
2019
Q2 		$386K Sell
6,000
-1,200
-17% -$84.8K 0.02% 347
2019
Q1 		$585K Sell
7,200
-2,100
-23% -$135K 0.04% 284
2018
Q4 		$503K Buy
9,300
+1,200
+15% +$61.2K 0.03% 284
2018
Q3 		$418K Buy
+8,100
New +$381K 0.02% 326
2018
Q2 		– Sell
-8,000
Closed -$352K – 551
2018
Q1 		$352K Sell
8,000
-14,000
-64% -$711K 0.02% 350
2017
Q4 		$1.11M Buy
22,000
+10,000
+83% +$548K 0.05% 220
2017
Q3 		$608K Buy
+12,000
New +$629K 0.03% 320
2016
Q1 		– Sell
-5,000
Closed -$310K – 699
2015
Q4 		$310K Buy
+5,000
New +$270K 0.02% 464
2014
Q3 		– Sell
-10,000
Closed -$344K – 772
2014
Q2 		$344K Buy
+10,000
New +$315K 0.01% 542

Other funds holding IONS

Fidelity Investments
Fidelity Investments Boston, Massachusetts $2.3T AUM 54.33% 1-Year Est. Return
Capital World Investors
Capital World Investors Los Angeles, California $846B AUM 46.74% 1-Year Est. Return
BlackRock
BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return
Vanguard Portfolio Management
Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM
Wellington Management Group
Wellington Management Group Boston, Massachusetts $580B AUM 38.23% 1-Year Est. Return
Vanguard Capital Management
Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM
Two Sigma Investments
Two Sigma Investments New York $138B AUM 41.87% 1-Year Est. Return
Royal Bank of Canada
Royal Bank of Canada Toronto, Ontario, Canada $672B AUM 33.48% 1-Year Est. Return
State Street
State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return
T. Rowe Price Investment Management
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.