Brown Brothers Harriman & Co’s Ionis Pharmaceuticals IONS Stock Holding History

Brown Brothers Harriman & Co’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	$27K	Hold	341	–	–	﹤0.01%	1225
2026 Q1	$25.6K	Hold	341	–	–	﹤0.01%	1178
2025 Q4	$27K	Buy	+341	New	+$25.7K	﹤0.01%	1150
2021 Q3	–	Sell	-200	Closed	-$8K	–	1194
2021 Q2	$8K	Sell	200 -2,150	-91%	-$84.2K	﹤0.01%	926
2021 Q1	$106K	Buy	2,350 +2,150	+1,075%	+$120K	﹤0.01%	512
2020 Q4	$11K	Buy	+200	New	+$9.97K	﹤0.01%	851
2020 Q2	–	Sell	-360	Closed	-$17K	–	1080
2020 Q1	$17K	Sell	360 -184	-34%	-$10.3K	﹤0.01%	649
2019 Q4	$33K	Sell	544 -6	-1%	-$357	﹤0.01%	729
2019 Q3	$33K	Buy	550 +179	+48%	+$11.7K	﹤0.01%	720
2019 Q2	$24K	Buy	371 +66	+22%	+$4.67K	﹤0.01%	701
2019 Q1	$25K	Buy	305 +123	+68%	+$7.93K	﹤0.01%	693
2018 Q4	$10K	Hold	182	–	–	﹤0.01%	693
2018 Q3	$9K	Hold	182	–	–	﹤0.01%	689
2018 Q2	$8K	Hold	182	–	–	﹤0.01%	691
2018 Q1	$8K	Sell	182 -95	-34%	-$4.83K	﹤0.01%	680
2017 Q4	$14K	Buy	277 +95	+52%	+$5.21K	﹤0.01%	707
2017 Q3	$9K	Hold	182	–	–	﹤0.01%	668
2017 Q2	$9K	Buy	+182	New	+$8.47K	﹤0.01%	667
2014 Q2	–	Sell	-17	Closed	-$1K	–	778
2014 Q1	$1K	Buy	+17	New	+$824	﹤0.01%	772

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

Brown Brothers Harriman & Co's IONS Position: Q2 2026 in Review

Brown Brothers Harriman & Co held its Ionis Pharmaceuticals (IONS) position steady in Q2 2026 at 341 shares worth $27K. The position accounts for ﹤0.01% of the portfolio, ranked #1225.

Brown Brothers Harriman & Co first reported a position in IONS in Q1 2014 and has held it in 19 quarters since. The position peaked at $106K in Q1 2021. 514 funds tracked by Wall St. Rank hold IONS as of Q2 2026.

Brown Brothers Harriman & Co held 341 shares of Ionis Pharmaceuticals worth $27K as of Q2 2026.
Brown Brothers Harriman & Co left its Ionis Pharmaceuticals share count unchanged in Q2 2026.
Ionis Pharmaceuticals made up ﹤0.01% of Brown Brothers Harriman & Co's portfolio in Q2 2026, its #1225 holding.
Brown Brothers Harriman & Co first reported a position in Ionis Pharmaceuticals in Q1 2014 and has held it in 19 quarters since.
Brown Brothers Harriman & Co's Ionis Pharmaceuticals position peaked at $106K in Q1 2021.
514 funds tracked by Wall St. Rank held Ionis Pharmaceuticals as of Q2 2026.

Based on Brown Brothers Harriman & Co's 13F filing for Q2 2026, filed 12 Aug 2026.