Baker Bros. Advisors’s Ionis Pharmaceuticals IONS Stock Holding History

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q1	$154M	Buy	2,047,727 +255,886	+14%	+$20.2M	0.88%	16
2025 Q4	$142M	Buy	1,791,841 +1,225,043	+216%	+$92.2M	0.83%	17
2025 Q3	$37.1M	Buy	+566,798	New	+$27.7M	0.27%	35
2025 Q2	–	Sell	-357,915	Closed	-$10.8M	–	93
2025 Q1	$10.8M	Hold	357,915	–	–	0.12%	45
2024 Q4	$12.5M	Buy	357,915 +134,445	+60%	+$5.03M	0.13%	49
2024 Q3	$8.95M	Buy	+223,470	New	+$10.4M	0.09%	55
2017 Q1	–	Sell	-57,140	Closed	-$2.73M	–	125
2016 Q4	$2.73M	Hold	57,140	–	–	0.03%	81
2016 Q3	$2.09M	Hold	57,140	–	–	0.02%	95
2016 Q2	$1.33M	Hold	57,140	–	–	0.01%	110
2016 Q1	$2.31M	Hold	57,140	–	–	0.02%	96
2015 Q4	$3.54M	Hold	57,140	–	–	0.03%	88
2015 Q3	$2.31M	Hold	57,140	–	–	0.02%	100
2015 Q2	$3.29M	Hold	57,140	–	–	0.03%	90
2015 Q1	$3.64M	Sell	57,140 -39,163	-41%	-$2.66M	0.03%	86
2014 Q4	$5.95M	Hold	96,303	–	–	0.06%	68
2014 Q3	$3.74M	Hold	96,303	–	–	0.05%	72
2014 Q2	$3.32M	Hold	96,303	–	–	0.04%	79
2014 Q1	$4.16M	Sell	96,303 -150,733	-61%	-$7.31M	0.05%	80
2013 Q4	$9.84M	Hold	247,036	–	–	0.14%	45
2013 Q3	$9.27M	Hold	247,036	–	–	0.13%	46
2013 Q2	$6.64M	Buy	+247,036	New	+$5.25M	0.13%	44