BIOGEN INC

Ticker: BIIB CUSIP: 09062X103 Class: COM

GATEWAY INVESTMENT ADVISERS LLC's Holding History (CIK: 0001114618)

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

Q4 2025

Shares 48,161 Value ($000) $8,476 Avg Close $163.37 Range $138.00 - $185.17

Q3 2025

Shares 42,326 Value ($000) $5,929 Avg Close $135.17 Range $121.05 - $150.28

Q2 2025

Shares 40,475 Value ($000) $5,083 Avg Close $124.60 Range $110.04 - $137.32

Q1 2025

Shares 41,259 Value ($000) $5,646 Avg Close $142.96 Range $128.51 - $157.09

Q4 2024

Shares 41,202 Value ($000) $6,301 Avg Close $168.67 Range $145.07 - $195.00

Q3 2024

Shares 41,312 Value ($000) $8,008 Avg Close $209.21 Range $188.78 - $238.00

Q2 2024

Shares 41,389 Value ($000) $9,595 Avg Close $217.32 Range $189.44 - $237.54

Q1 2024

Shares 41,434 Value ($000) $8,934 Avg Close $234.20 Range $211.02 - $268.30

Q4 2023

Shares 46,939 Value ($000) $12,146 Avg Close $245.62 Range $220.86 - $269.43

Q3 2023

Shares 52,836 Value ($000) $13,579 Avg Close $267.47 Range $251.85 - $287.60

Q2 2023

Shares 52,992 Value ($000) $15,095 Avg Close $297.86 Range $273.39 - $319.76

Q1 2023

Shares 66,436 Value ($000) $18,471 Avg Close $276.70 Range $254.80 - $295.90

Q4 2022

Shares 56,422 Value ($000) $15,624 Avg Close $282.44 Range $250.31 - $311.88

Q3 2022

Shares 70,817 Value ($000) $18,908 Avg Close $212.38 Range $193.65 - $283.44

Q2 2022

Shares 70,894 Value ($000) $14,458 Avg Close $204.43 Range $187.16 - $225.50

Q1 2022

Shares 59,499 Value ($000) $12,530 Avg Close $217.46 Range $192.67 - $249.00

Q4 2021

Shares 55,030 Value ($000) $13,203 Avg Close $257.12 Range $221.72 - $290.76

Q3 2021

Shares 61,812 Value ($000) $17,492 Avg Close $327.75 Range $282.64 - $372.12

Q2 2021

Shares 61,810 Value ($000) $21,403 Avg Close $302.94 Range $257.03 - $468.55

Q1 2021

Shares 62,074 Value ($000) $17,365 Avg Close $269.69 Range $238.40 - $296.38

Q4 2020

Shares 67,807 Value ($000) $16,603 Avg Close $259.08 Range $223.25 - $363.92

Q3 2020

Shares 69,702 Value ($000) $19,773 Avg Close $278.91 Range $261.87 - $312.00

Q2 2020

Shares 81,373 Value ($000) $21,771 Avg Close $300.59 Range $257.60 - $350.24

Q1 2020

Shares 88,091 Value ($000) $27,870 Avg Close $303.47 Range $262.25 - $374.99

Q4 2019

Shares 96,162 Value ($000) $28,534 Avg Close $277.46 Range $219.70 - $318.00

Q3 2019

Shares 122,855 Value ($000) $28,603 Avg Close $232.85 Range $215.78 - $246.99

Q2 2019

Shares 140,203 Value ($000) $32,789 Avg Close $230.90 Range $219.20 - $245.35

Q1 2019

Shares 127,314 Value ($000) $30,094 Avg Close $314.89 Range $216.12 - $344.00

Q4 2018

Shares 128,214 Value ($000) $38,582 Avg Close $319.14 Range $278.46 - $358.41

Q3 2018

Shares 120,863 Value ($000) $42,702 Avg Close $344.30 Range $288.13 - $388.67

Q2 2018

Shares 129,197 Value ($000) $37,498 Avg Close $281.15 Range $249.17 - $310.91

Q1 2018

Shares 135,431 Value ($000) $37,084 Avg Close $310.41 Range $259.76 - $370.57

Q4 2017

Shares 141,367 Value ($000) $45,035 Avg Close $320.80 Range $301.81 - $348.84

Q3 2017

Shares 148,605 Value ($000) $46,531 Avg Close $296.11 Range $269.50 - $330.00

Q2 2017

Shares 160,003 Value ($000) $43,418 Avg Close $264.42 Range $244.28 - $291.90

Q1 2017

Shares 144,743 Value ($000) $39,576 Avg Close $282.75 Range $260.50 - $301.42

Q4 2016

Shares 151,785 Value ($000) $43,043 Avg Close $296.43 Range $268.00 - $329.83

Q3 2016

Shares 161,550 Value ($000) $50,570 Avg Close $296.18 Range $240.07 - $333.65

Q2 2016

Shares 173,476 Value ($000) $41,950 Avg Close $263.54 Range $223.02 - $292.69

Q1 2016

Shares 172,519 Value ($000) $44,910 Avg Close $264.15 Range $242.07 - $301.02

Q4 2015

Shares 165,637 Value ($000) $50,743 Avg Close $287.35 Range $254.00 - $311.65

Q3 2015

Shares 167,301 Value ($000) $48,820 Avg Close $330.23 Range $265.00 - $412.24

Q2 2015

Shares 152,405 Value ($000) $61,562 Avg Close $401.33 Range $368.88 - $432.88

Q1 2015

Shares 157,078 Value ($000) $66,325 Avg Close $394.14 Range $334.40 - $480.18

Q4 2014

Shares 157,042 Value ($000) $53,308 Avg Close $323.51 Range $290.85 - $361.93

Q3 2014

Shares 163,073 Value ($000) $53,946 Avg Close $329.72 Range $298.31 - $349.00

Q2 2014

Shares 187,387 Value ($000) $59,085 Avg Close $300.97 Range $272.02 - $322.25

Q1 2014

Shares 184,809 Value ($000) $56,528 Avg Close $317.43 Range $270.62 - $358.89

Q4 2013

Shares 180,025 Value ($000) $50,362 Avg Close $258.65 Range $221.07 - $298.82

Q3 2013

Shares 180,615 Value ($000) $43,485 Avg Close $223.81 Range $203.55 - $248.95

Q2 2013

Shares 179,976 Value ($000) $38,731 Avg Close $213.68 Range $191.80 - $242.64

Period	Shares	Value ($000)	Average Close	Price Range
Q4 2025	48,161	$8,476	$163.37	$138.00 - $185.17
Q3 2025	42,326	$5,929	$135.17	$121.05 - $150.28
Q2 2025	40,475	$5,083	$124.60	$110.04 - $137.32
Q1 2025	41,259	$5,646	$142.96	$128.51 - $157.09
Q4 2024	41,202	$6,301	$168.67	$145.07 - $195.00
Q3 2024	41,312	$8,008	$209.21	$188.78 - $238.00
Q2 2024	41,389	$9,595	$217.32	$189.44 - $237.54
Q1 2024	41,434	$8,934	$234.20	$211.02 - $268.30
Q4 2023	46,939	$12,146	$245.62	$220.86 - $269.43
Q3 2023	52,836	$13,579	$267.47	$251.85 - $287.60
Q2 2023	52,992	$15,095	$297.86	$273.39 - $319.76
Q1 2023	66,436	$18,471	$276.70	$254.80 - $295.90
Q4 2022	56,422	$15,624	$282.44	$250.31 - $311.88
Q3 2022	70,817	$18,908	$212.38	$193.65 - $283.44
Q2 2022	70,894	$14,458	$204.43	$187.16 - $225.50
Q1 2022	59,499	$12,530	$217.46	$192.67 - $249.00
Q4 2021	55,030	$13,203	$257.12	$221.72 - $290.76
Q3 2021	61,812	$17,492	$327.75	$282.64 - $372.12
Q2 2021	61,810	$21,403	$302.94	$257.03 - $468.55
Q1 2021	62,074	$17,365	$269.69	$238.40 - $296.38
Q4 2020	67,807	$16,603	$259.08	$223.25 - $363.92
Q3 2020	69,702	$19,773	$278.91	$261.87 - $312.00
Q2 2020	81,373	$21,771	$300.59	$257.60 - $350.24
Q1 2020	88,091	$27,870	$303.47	$262.25 - $374.99
Q4 2019	96,162	$28,534	$277.46	$219.70 - $318.00
Q3 2019	122,855	$28,603	$232.85	$215.78 - $246.99
Q2 2019	140,203	$32,789	$230.90	$219.20 - $245.35
Q1 2019	127,314	$30,094	$314.89	$216.12 - $344.00
Q4 2018	128,214	$38,582	$319.14	$278.46 - $358.41
Q3 2018	120,863	$42,702	$344.30	$288.13 - $388.67
Q2 2018	129,197	$37,498	$281.15	$249.17 - $310.91
Q1 2018	135,431	$37,084	$310.41	$259.76 - $370.57
Q4 2017	141,367	$45,035	$320.80	$301.81 - $348.84
Q3 2017	148,605	$46,531	$296.11	$269.50 - $330.00
Q2 2017	160,003	$43,418	$264.42	$244.28 - $291.90
Q1 2017	144,743	$39,576	$282.75	$260.50 - $301.42
Q4 2016	151,785	$43,043	$296.43	$268.00 - $329.83
Q3 2016	161,550	$50,570	$296.18	$240.07 - $333.65
Q2 2016	173,476	$41,950	$263.54	$223.02 - $292.69
Q1 2016	172,519	$44,910	$264.15	$242.07 - $301.02
Q4 2015	165,637	$50,743	$287.35	$254.00 - $311.65
Q3 2015	167,301	$48,820	$330.23	$265.00 - $412.24
Q2 2015	152,405	$61,562	$401.33	$368.88 - $432.88
Q1 2015	157,078	$66,325	$394.14	$334.40 - $480.18
Q4 2014	157,042	$53,308	$323.51	$290.85 - $361.93
Q3 2014	163,073	$53,946	$329.72	$298.31 - $349.00
Q2 2014	187,387	$59,085	$300.97	$272.02 - $322.25
Q1 2014	184,809	$56,528	$317.43	$270.62 - $358.89
Q4 2013	180,025	$50,362	$258.65	$221.07 - $298.82
Q3 2013	180,615	$43,485	$223.81	$203.55 - $248.95
Q2 2013	179,976	$38,731	$213.68	$191.80 - $242.64