Brown Brothers Harriman & Co’s Biogen BIIB Stock Holding History

Brown Brothers Harriman & Co’s Portfolio BIIB Stock Details BIIB Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2026 Q2	$2.01M	Buy	9,312 +3,019	+48%	+$578K	0.01%	358
2026 Q1	$1.15M	Buy	6,293 +1,309	+26%	+$241K	0.01%	403
2025 Q4	$877K	Buy	4,984 +288	+6%	+$47.1K	﹤0.01%	401
2025 Q3	$658K	Sell	4,696 -427	-8%	-$57.7K	﹤0.01%	426
2025 Q2	$643K	Buy	5,123 +659	+15%	+$82.1K	﹤0.01%	410
2025 Q1	$611K	Sell	4,464 -149	-3%	-$21.3K	﹤0.01%	374
2024 Q4	$705K	Sell	4,613 -358	-7%	-$60.4K	﹤0.01%	348
2024 Q3	$964K	Sell	4,971 -354	-7%	-$74.1K	0.01%	298
2024 Q2	$1.23M	Sell	5,325 -191	-3%	-$41.5K	0.01%	239
2024 Q1	$1.19M	Sell	5,516 -451	-8%	-$106K	0.01%	242
2023 Q4	$1.54M	Hold	5,967	–	–	0.01%	213
2023 Q3	$1.53M	Hold	5,967	–	–	0.01%	206
2023 Q2	$1.7M	Sell	5,967 -803	-12%	-$239K	0.01%	193
2023 Q1	$1.88M	Buy	6,770 +32	+0.5%	+$8.85K	0.02%	181
2022 Q4	$1.87M	Buy	6,738 +774	+13%	+$219K	0.02%	161
2022 Q3	$1.59M	Buy	5,964 +26	+0.4%	+$5.52K	0.01%	173
2022 Q2	$1.21M	Hold	5,938	–	–	0.01%	193
2022 Q1	$1.25M	Buy	5,938 +573	+11%	+$125K	0.01%	214
2021 Q4	$1.29M	Sell	5,365 -529	-9%	-$136K	0.01%	218
2021 Q3	$1.67M	Hold	5,894	–	–	0.01%	177
2021 Q2	$2.04M	Sell	5,894 -417	-7%	-$126K	0.01%	166
2021 Q1	$1.77M	Buy	6,311 +1,271	+25%	+$343K	0.01%	171
2020 Q4	$1.23M	Buy	5,040 +1,014	+25%	+$262K	0.01%	199
2020 Q3	$1.14M	Sell	4,026 -50	-1%	-$13.9K	0.01%	199
2020 Q2	$1.09M	Buy	4,076 +279	+7%	+$83.9K	0.01%	195
2020 Q1	$1.2M	Sell	3,797 -11	-0.3%	-$3.34K	0.01%	175
2019 Q4	$1.13M	Sell	3,808 -704	-16%	-$195K	0.01%	231
2019 Q3	$1.05M	Buy	4,512 +819	+22%	+$191K	0.01%	221
2019 Q2	$864K	Buy	3,693 +250	+7%	+$57.7K	0.01%	229
2019 Q1	$814K	Buy	3,443 +388	+13%	+$122K	0.01%	219
2018 Q4	$919K	Buy	3,055 +50	+2%	+$16K	0.01%	204
2018 Q3	$1.06M	Buy	3,005 +75	+3%	+$25.8K	0.01%	195
2018 Q2	$850K	Sell	2,930 -78	-3%	-$21.9K	0.01%	194
2018 Q1	$824K	Sell	3,008 -68	-2%	-$21.1K	﹤0.01%	202
2017 Q4	$980K	Buy	3,076 +96	+3%	+$30.8K	0.01%	186
2017 Q3	$933K	Sell	2,980 -28	-0.9%	-$8.29K	0.01%	185
2017 Q2	$816K	Sell	3,008 -257	-8%	-$68K	﹤0.01%	191
2017 Q1	$893K	Sell	3,265 -183	-5%	-$51.7K	﹤0.01%	179
2016 Q4	$978K	Sell	3,448 -4,253	-55%	-$1.26M	0.01%	166
2016 Q3	$2.41M	Sell	7,701 -2,798	-27%	-$829K	0.01%	127
2016 Q2	$2.54M	Sell	10,499 -1,175	-10%	-$310K	0.01%	131
2016 Q1	$3.04M	Buy	11,674 +378	+3%	+$99.8K	0.02%	119
2015 Q4	$3.46M	Buy	11,296 +424	+4%	+$122K	0.02%	114
2015 Q3	$3.17M	Buy	10,872 +3,496	+47%	+$1.15M	0.02%	117
2015 Q2	$2.98M	Buy	7,376 +2,187	+42%	+$878K	0.01%	123
2015 Q1	$2.19M	Buy	5,189 +2,624	+102%	+$1.03M	0.01%	143
2014 Q4	$871K	Hold	2,565	–	–	﹤0.01%	212
2014 Q3	$849K	Hold	2,565	–	–	﹤0.01%	210
2014 Q2	$809K	Sell	2,565 -58	-2%	-$17.5K	﹤0.01%	220
2014 Q1	$802K	Sell	2,623 -2,561	-49%	-$813K	﹤0.01%	199
2013 Q4	$1.45M	Buy	5,184 +2,603	+101%	+$673K	﹤0.01%	208
2013 Q3	$621K	Sell	2,581 -652	-20%	-$146K	﹤0.01%	212
2013 Q2	$696K	Buy	+3,233	New	+$691K	﹤0.01%	247

Other funds holding BIIB

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

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

Primecap Management Pasadena, California $169B AUM 114.72% 1-Year Est. Return

Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM

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

Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM

Geode Capital Management Boston, Massachusetts $1.88T AUM 44.46% 1-Year Est. Return

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

Norges Bank Oslo, Norway $1T AUM

Morgan Stanley New York $1.89T AUM 35.08% 1-Year Est. Return

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

Brown Brothers Harriman & Co increased its Biogen (BIIB) stake by 48% in Q2 2026, buying an estimated $578K and bringing the position to 9,312 shares worth $2.01M. The position accounts for 0.01% of the portfolio, ranked #358.

Brown Brothers Harriman & Co first reported a position in BIIB in Q2 2013 and has held it in 53 quarters since. The position peaked at $3.46M in Q4 2015. 1,041 funds tracked by Wall St. Rank hold BIIB as of Q2 2026.

Brown Brothers Harriman & Co held 9,312 shares of Biogen worth $2.01M as of Q2 2026.
Brown Brothers Harriman & Co bought 3,019 Biogen shares in Q2 2026, an estimated $578K.
Biogen made up 0.01% of Brown Brothers Harriman & Co's portfolio in Q2 2026, its #358 holding.
Brown Brothers Harriman & Co first reported a position in Biogen in Q2 2013 and has held it in 53 quarters since.
Brown Brothers Harriman & Co's Biogen position peaked at $3.46M in Q4 2015.
1,041 funds tracked by Wall St. Rank held Biogen as of Q2 2026.

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