BIOGEN INC

Ticker: BIIB CUSIP: 09062X103 Class: COM

BROWN BROTHERS HARRIMAN & CO's Holding History (CIK: 0000014661)

Note: Option positions (PUT/CALL) are excluded.

Q4 2025

Shares 4,984 Value ($000) $877 Avg Close $163.37 Range $138.00 - $185.17

Q3 2025

Shares 4,696 Value ($000) $658 Avg Close $135.17 Range $121.05 - $150.28

Q2 2025

Shares 5,123 Value ($000) $643 Avg Close $124.60 Range $110.04 - $137.32

Q1 2025

Shares 4,464 Value ($000) $611 Avg Close $142.96 Range $128.51 - $157.09

Q4 2024

Shares 4,613 Value ($000) $705 Avg Close $168.67 Range $145.07 - $195.00

Q3 2024

Shares 4,971 Value ($000) $964 Avg Close $209.21 Range $188.78 - $238.00

Q2 2024

Shares 5,325 Value ($000) $1,234 Avg Close $217.32 Range $189.44 - $237.54

Q1 2024

Shares 5,516 Value ($000) $1,189 Avg Close $234.20 Range $211.02 - $268.30

Q4 2023

Shares 5,967 Value ($000) $1,544 Avg Close $245.62 Range $220.86 - $269.43

Q3 2023

Shares 5,967 Value ($000) $1,534 Avg Close $267.47 Range $251.85 - $287.60

Q2 2023

Shares 5,967 Value ($000) $1,700 Avg Close $297.86 Range $273.39 - $319.76

Q1 2023

Shares 6,770 Value ($000) $1,882 Avg Close $276.70 Range $254.80 - $295.90

Q4 2022

Shares 6,738 Value ($000) $1,866 Avg Close $282.44 Range $250.31 - $311.88

Q3 2022

Shares 5,964 Value ($000) $1,592 Avg Close $212.38 Range $193.65 - $283.44

Q2 2022

Shares 5,938 Value ($000) $1,211 Avg Close $204.43 Range $187.16 - $225.50

Q1 2022

Shares 5,938 Value ($000) $1,251 Avg Close $217.46 Range $192.67 - $249.00

Q4 2021

Shares 5,365 Value ($000) $1,287 Avg Close $257.12 Range $221.72 - $290.76

Q3 2021

Shares 5,894 Value ($000) $1,668 Avg Close $327.75 Range $282.64 - $372.12

Q2 2021

Shares 5,894 Value ($000) $2,041 Avg Close $302.94 Range $257.03 - $468.55

Q1 2021

Shares 6,311 Value ($000) $1,766 Avg Close $269.69 Range $238.40 - $296.38

Q4 2020

Shares 5,040 Value ($000) $1,234 Avg Close $259.08 Range $223.25 - $363.92

Q3 2020

Shares 4,026 Value ($000) $1,142 Avg Close $278.91 Range $261.87 - $312.00

Q2 2020

Shares 4,076 Value ($000) $1,091 Avg Close $300.59 Range $257.60 - $350.24

Q1 2020

Shares 3,797 Value ($000) $1,201 Avg Close $303.47 Range $262.25 - $374.99

Q4 2019

Shares 3,808 Value ($000) $1,130 Avg Close $277.46 Range $219.70 - $318.00

Q3 2019

Shares 4,512 Value ($000) $1,050 Avg Close $232.85 Range $215.78 - $246.99

Q2 2019

Shares 3,693 Value ($000) $864 Avg Close $230.90 Range $219.20 - $245.35

Q1 2019

Shares 3,443 Value ($000) $814 Avg Close $314.89 Range $216.12 - $344.00

Q4 2018

Shares 3,055 Value ($000) $919 Avg Close $319.14 Range $278.46 - $358.41

Q3 2018

Shares 3,005 Value ($000) $1,062 Avg Close $344.30 Range $288.13 - $388.67

Q2 2018

Shares 2,930 Value ($000) $850 Avg Close $281.15 Range $249.17 - $310.91

Q1 2018

Shares 3,008 Value ($000) $824 Avg Close $310.41 Range $259.76 - $370.57

Q4 2017

Shares 3,076 Value ($000) $980 Avg Close $320.80 Range $301.81 - $348.84

Q3 2017

Shares 2,980 Value ($000) $933 Avg Close $296.11 Range $269.50 - $330.00

Q2 2017

Shares 3,008 Value ($000) $816 Avg Close $264.42 Range $244.28 - $291.90

Q1 2017

Shares 3,265 Value ($000) $893 Avg Close $282.75 Range $260.50 - $301.42

Q4 2016

Shares 3,448 Value ($000) $978 Avg Close $296.43 Range $268.00 - $329.83

Q3 2016

Shares 7,701 Value ($000) $2,411 Avg Close $296.18 Range $240.07 - $333.65

Q2 2016

Shares 10,499 Value ($000) $2,539 Avg Close $263.54 Range $223.02 - $292.69

Q1 2016

Shares 11,674 Value ($000) $3,039 Avg Close $264.15 Range $242.07 - $301.02

Q4 2015

Shares 11,296 Value ($000) $3,461 Avg Close $287.35 Range $254.00 - $311.65

Q3 2015

Shares 10,872 Value ($000) $3,173 Avg Close $330.23 Range $265.00 - $412.24

Q2 2015

Shares 7,376 Value ($000) $2,979 Avg Close $401.33 Range $368.88 - $432.88

Q1 2015

Shares 5,189 Value ($000) $2,191 Avg Close $394.14 Range $334.40 - $480.18

Q4 2014

Shares 2,565 Value ($000) $871 Avg Close $323.51 Range $290.85 - $361.93

Q3 2014

Shares 2,565 Value ($000) $849 Avg Close $329.72 Range $298.31 - $349.00

Q2 2014

Shares 2,565 Value ($000) $809 Avg Close $300.97 Range $272.02 - $322.25

Q1 2014

Shares 2,623 Value ($000) $802 Avg Close $317.43 Range $270.62 - $358.89

Q4 2013

Shares 2,592 Value ($000) $725 Avg Close $258.65 Range $221.07 - $298.82

Q3 2013

Shares 2,581 Value ($000) $621 Avg Close $223.81 Range $203.55 - $248.95

Q2 2013

Shares 3,233 Value ($000) $696 Avg Close $213.68 Range $191.80 - $242.64

Q1 2013

Shares 2,983 Value ($000) $575 Avg Close $161.63 Range $139.72 - $192.92

Period	Shares	Value ($000)	Average Close	Price Range
Q4 2025	4,984	$877	$163.37	$138.00 - $185.17
Q3 2025	4,696	$658	$135.17	$121.05 - $150.28
Q2 2025	5,123	$643	$124.60	$110.04 - $137.32
Q1 2025	4,464	$611	$142.96	$128.51 - $157.09
Q4 2024	4,613	$705	$168.67	$145.07 - $195.00
Q3 2024	4,971	$964	$209.21	$188.78 - $238.00
Q2 2024	5,325	$1,234	$217.32	$189.44 - $237.54
Q1 2024	5,516	$1,189	$234.20	$211.02 - $268.30
Q4 2023	5,967	$1,544	$245.62	$220.86 - $269.43
Q3 2023	5,967	$1,534	$267.47	$251.85 - $287.60
Q2 2023	5,967	$1,700	$297.86	$273.39 - $319.76
Q1 2023	6,770	$1,882	$276.70	$254.80 - $295.90
Q4 2022	6,738	$1,866	$282.44	$250.31 - $311.88
Q3 2022	5,964	$1,592	$212.38	$193.65 - $283.44
Q2 2022	5,938	$1,211	$204.43	$187.16 - $225.50
Q1 2022	5,938	$1,251	$217.46	$192.67 - $249.00
Q4 2021	5,365	$1,287	$257.12	$221.72 - $290.76
Q3 2021	5,894	$1,668	$327.75	$282.64 - $372.12
Q2 2021	5,894	$2,041	$302.94	$257.03 - $468.55
Q1 2021	6,311	$1,766	$269.69	$238.40 - $296.38
Q4 2020	5,040	$1,234	$259.08	$223.25 - $363.92
Q3 2020	4,026	$1,142	$278.91	$261.87 - $312.00
Q2 2020	4,076	$1,091	$300.59	$257.60 - $350.24
Q1 2020	3,797	$1,201	$303.47	$262.25 - $374.99
Q4 2019	3,808	$1,130	$277.46	$219.70 - $318.00
Q3 2019	4,512	$1,050	$232.85	$215.78 - $246.99
Q2 2019	3,693	$864	$230.90	$219.20 - $245.35
Q1 2019	3,443	$814	$314.89	$216.12 - $344.00
Q4 2018	3,055	$919	$319.14	$278.46 - $358.41
Q3 2018	3,005	$1,062	$344.30	$288.13 - $388.67
Q2 2018	2,930	$850	$281.15	$249.17 - $310.91
Q1 2018	3,008	$824	$310.41	$259.76 - $370.57
Q4 2017	3,076	$980	$320.80	$301.81 - $348.84
Q3 2017	2,980	$933	$296.11	$269.50 - $330.00
Q2 2017	3,008	$816	$264.42	$244.28 - $291.90
Q1 2017	3,265	$893	$282.75	$260.50 - $301.42
Q4 2016	3,448	$978	$296.43	$268.00 - $329.83
Q3 2016	7,701	$2,411	$296.18	$240.07 - $333.65
Q2 2016	10,499	$2,539	$263.54	$223.02 - $292.69
Q1 2016	11,674	$3,039	$264.15	$242.07 - $301.02
Q4 2015	11,296	$3,461	$287.35	$254.00 - $311.65
Q3 2015	10,872	$3,173	$330.23	$265.00 - $412.24
Q2 2015	7,376	$2,979	$401.33	$368.88 - $432.88
Q1 2015	5,189	$2,191	$394.14	$334.40 - $480.18
Q4 2014	2,565	$871	$323.51	$290.85 - $361.93
Q3 2014	2,565	$849	$329.72	$298.31 - $349.00
Q2 2014	2,565	$809	$300.97	$272.02 - $322.25
Q1 2014	2,623	$802	$317.43	$270.62 - $358.89
Q4 2013	2,592	$725	$258.65	$221.07 - $298.82
Q3 2013	2,581	$621	$223.81	$203.55 - $248.95
Q2 2013	3,233	$696	$213.68	$191.80 - $242.64
Q1 2013	2,983	$575	$161.63	$139.72 - $192.92