Arrowstreet Capital’s Ionis Pharmaceuticals IONS Stock Holding History

Arrowstreet Capital’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 Q1	$55.4M	Sell	737,859 -325,468	-31%	-$25.7M	0.03%	465
2025 Q4	$84.1M	Buy	1,063,327 +433,191	+69%	+$32.6M	0.05%	331
2025 Q3	$41.2M	Buy	+630,136	New	+$30.8M	0.03%	519
2022 Q3	–	Sell	-41,104	Closed	-$1.52M	–	1366
2022 Q2	$1.52M	Buy	+41,104	New	+$1.55M	﹤0.01%	843
2021 Q4	–	Sell	-41,100	Closed	-$1.38M	–	1569
2021 Q3	$1.38M	Sell	41,100 -51,800	-56%	-$1.95M	﹤0.01%	1214
2021 Q2	$3.71M	Buy	+92,900	New	+$3.64M	﹤0.01%	1158
2020 Q4	–	Sell	-26,000	Closed	-$1.23M	–	2408
2020 Q3	$1.23M	Buy	+26,000	New	+$1.44M	﹤0.01%	1755
2020 Q1	–	Sell	-14,157	Closed	-$855K	–	1983
2019 Q4	$855K	Sell	14,157 -1,843	-12%	-$110K	﹤0.01%	1377
2019 Q3	$959K	Buy	+16,000	New	+$1.04M	﹤0.01%	1177
2019 Q2	–	Sell	-184,174	Closed	-$14.9M	–	1525
2019 Q1	$14.9M	Buy	+184,174	New	+$11.9M	0.04%	438
2016 Q4	–	Sell	-704,855	Closed	-$25.8M	–	2072
2016 Q3	$25.8M	Buy	+704,855	New	+$22.1M	0.08%	235
2015 Q3	–	Sell	-387,915	Closed	-$22.3M	–	1420
2015 Q2	$22.3M	Buy	+387,915	New	+$24.7M	0.13%	170
2013 Q4	–	Sell	-155,564	Closed	-$5.84M	–	1218
2013 Q3	$5.84M	Buy	+155,564	New	+$4.65M	0.04%	353

Other funds holding IONS

Fidelity Investments Boston, Massachusetts $1.9T AUM 41.92% 1-Year Est. Return

Capital World Investors Los Angeles, California $733B AUM 35.63% 1-Year Est. Return

BlackRock New York $5.72T AUM 30.48% 1-Year Est. Return

VPM

Vanguard Portfolio Management Malvern, Pennsylvania $1.91T AUM

VCM

Vanguard Capital Management Malvern, Pennsylvania $4.04T AUM

Wellington Management Group Boston, Massachusetts $535B AUM 26.23% 1-Year Est. Return

T. Rowe Price Investment Management Baltimore, Maryland $145B AUM 22.78% 1-Year Est. Return

Two Sigma Investments New York $124B AUM 33.93% 1-Year Est. Return

Geode Capital Management Boston, Massachusetts $1.61T AUM 30.72% 1-Year Est. Return

State Street Boston, Massachusetts $2.9T AUM 29.55% 1-Year Est. Return

Arrowstreet Capital's IONS Position: Q1 2026 in Review

Arrowstreet Capital reduced its Ionis Pharmaceuticals (IONS) stake by 31% in Q1 2026, selling an estimated $25.7M and leaving 737,859 shares worth $55.4M. The position accounts for 0.03% of the portfolio, ranked #465.

Arrowstreet Capital first reported a position in IONS in Q3 2013 and has held it in 13 quarters since. The position peaked at $84.1M in Q4 2025. 493 funds tracked by Wall St. Rank hold IONS as of Q1 2026.

Arrowstreet Capital held 737,859 shares of Ionis Pharmaceuticals worth $55.4M as of Q1 2026.
Arrowstreet Capital sold 325,468 Ionis Pharmaceuticals shares in Q1 2026, an estimated $25.7M.
Ionis Pharmaceuticals made up 0.03% of Arrowstreet Capital's portfolio in Q1 2026, its #465 holding.
Arrowstreet Capital first reported a position in Ionis Pharmaceuticals in Q3 2013 and has held it in 13 quarters since.
Arrowstreet Capital's Ionis Pharmaceuticals position peaked at $84.1M in Q4 2025.
493 funds tracked by Wall St. Rank held Ionis Pharmaceuticals as of Q1 2026.

Based on Arrowstreet Capital's 13F filing for Q1 2026, filed 14 May 2026.