BIOGEN INC

Ticker: BIIB CUSIP: 09062X103 Class: COM

STATE OF WISCONSIN INVESTMENT BOARD's Holding History (CIK: 0000854157)

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

Q4 2025

Shares 75,944 Value ($000) $13,365 Avg Close $163.37 Range $138.00 - $185.17

Q3 2025

Shares 77,899 Value ($000) $10,912 Avg Close $135.17 Range $121.05 - $150.28

Q2 2025

Shares 78,768 Value ($000) $9,892 Avg Close $124.60 Range $110.04 - $137.32

Q1 2025

Shares 88,576 Value ($000) $12,121 Avg Close $142.96 Range $128.51 - $157.09

Q4 2024

Shares 80,141 Value ($000) $12,255 Avg Close $168.67 Range $145.07 - $195.00

Q3 2024

Shares 92,966 Value ($000) $18,021 Avg Close $209.21 Range $188.78 - $238.00

Q2 2024

Shares 79,395 Value ($000) $18,405 Avg Close $217.32 Range $189.44 - $237.54

Q1 2024

Shares 88,563 Value ($000) $19,097 Avg Close $234.20 Range $211.02 - $268.30

Q4 2023

Shares 77,562 Value ($000) $20,071 Avg Close $245.62 Range $220.86 - $269.43

Q3 2023

Shares 81,291 Value ($000) $20,893 Avg Close $267.47 Range $251.85 - $287.60

Q2 2023

Shares 111,498 Value ($000) $31,760 Avg Close $297.86 Range $273.39 - $319.76

Q1 2023

Shares 98,821 Value ($000) $27,475 Avg Close $276.70 Range $254.80 - $295.90

Q4 2022

Shares 93,373 Value ($000) $25,857 Avg Close $282.44 Range $250.31 - $311.88

Q3 2022

Shares 92,993 Value ($000) $24,829 Avg Close $212.38 Range $193.65 - $283.44

Q2 2022

Shares 121,162 Value ($000) $24,710 Avg Close $204.43 Range $187.16 - $225.50

Q1 2022

Shares 128,668 Value ($000) $27,097 Avg Close $217.46 Range $192.67 - $249.00

Q4 2021

Shares 135,563 Value ($000) $32,524 Avg Close $257.12 Range $221.72 - $290.76

Q3 2021

Shares 155,112 Value ($000) $43,895 Avg Close $327.75 Range $282.64 - $372.12

Q2 2021

Shares 291,563 Value ($000) $100,959 Avg Close $302.94 Range $257.03 - $468.55

Q1 2021

Shares 151,188 Value ($000) $42,295 Avg Close $269.69 Range $238.40 - $296.38

Q4 2020

Shares 187,435 Value ($000) $45,895 Avg Close $259.08 Range $223.25 - $363.92

Q3 2020

Shares 118,801 Value ($000) $33,701 Avg Close $278.91 Range $261.87 - $312.00

Q2 2020

Shares 102,890 Value ($000) $27,528 Avg Close $300.59 Range $257.60 - $350.24

Q1 2020

Shares 108,329 Value ($000) $34,273 Avg Close $303.47 Range $262.25 - $374.99

Q4 2019

Shares 155,313 Value ($000) $46,086 Avg Close $277.46 Range $219.70 - $318.00

Q3 2019

Shares 184,021 Value ($000) $42,844 Avg Close $232.85 Range $215.78 - $246.99

Q2 2019

Shares 255,076 Value ($000) $59,655 Avg Close $230.90 Range $219.20 - $245.35

Q1 2019

Shares 292,784 Value ($000) $69,208 Avg Close $314.89 Range $216.12 - $344.00

Q4 2018

Shares 294,161 Value ($000) $88,519 Avg Close $319.14 Range $278.46 - $358.41

Q3 2018

Shares 268,851 Value ($000) $94,988 Avg Close $344.30 Range $288.13 - $388.67

Q2 2018

Shares 356,033 Value ($000) $103,335 Avg Close $281.15 Range $249.17 - $310.91

Q1 2018

Shares 370,247 Value ($000) $101,381 Avg Close $310.41 Range $259.76 - $370.57

Q4 2017

Shares 330,865 Value ($000) $105,404 Avg Close $320.80 Range $301.81 - $348.84

Q3 2017

Shares 348,260 Value ($000) $109,047 Avg Close $296.11 Range $269.50 - $330.00

Q2 2017

Shares 213,506 Value ($000) $57,937 Avg Close $264.42 Range $244.28 - $291.90

Q1 2017

Shares 185,796 Value ($000) $50,800 Avg Close $282.75 Range $260.50 - $301.42

Q4 2016

Shares 252,657 Value ($000) $71,648 Avg Close $296.43 Range $268.00 - $329.83

Q3 2016

Shares 228,501 Value ($000) $71,528 Avg Close $296.18 Range $240.07 - $333.65

Q2 2016

Shares 206,741 Value ($000) $49,994 Avg Close $263.54 Range $223.02 - $292.69

Q1 2016

Shares 172,991 Value ($000) $45,033 Avg Close $264.15 Range $242.07 - $301.02

Q4 2015

Shares 193,175 Value ($000) $59,179 Avg Close $287.35 Range $254.00 - $311.65

Q3 2015

Shares 220,265 Value ($000) $64,276 Avg Close $330.23 Range $265.00 - $412.24

Q2 2015

Shares 193,061 Value ($000) $77,985 Avg Close $401.33 Range $368.88 - $432.88

Q1 2015

Shares 216,336 Value ($000) $91,346 Avg Close $394.14 Range $334.40 - $480.18

Q4 2014

Shares 288,766 Value ($000) $98,022 Avg Close $323.51 Range $290.85 - $361.93

Q3 2014

Shares 227,956 Value ($000) $75,410 Avg Close $329.72 Range $298.31 - $349.00

Q2 2014

Shares 266,776 Value ($000) $84,117 Avg Close $300.97 Range $272.02 - $322.25

Q1 2014

Shares 278,319 Value ($000) $85,129 Avg Close $317.43 Range $270.62 - $358.89

Q4 2013

Shares 263,099 Value ($000) $73,602 Avg Close $258.65 Range $221.07 - $298.82

Q3 2013

Shares 319,032 Value ($000) $76,810 Avg Close $223.81 Range $203.55 - $248.95

Q2 2013

Shares 372,572 Value ($000) $80,177 Avg Close $213.68 Range $191.80 - $242.64

Period	Shares	Value ($000)	Average Close	Price Range
Q4 2025	75,944	$13,365	$163.37	$138.00 - $185.17
Q3 2025	77,899	$10,912	$135.17	$121.05 - $150.28
Q2 2025	78,768	$9,892	$124.60	$110.04 - $137.32
Q1 2025	88,576	$12,121	$142.96	$128.51 - $157.09
Q4 2024	80,141	$12,255	$168.67	$145.07 - $195.00
Q3 2024	92,966	$18,021	$209.21	$188.78 - $238.00
Q2 2024	79,395	$18,405	$217.32	$189.44 - $237.54
Q1 2024	88,563	$19,097	$234.20	$211.02 - $268.30
Q4 2023	77,562	$20,071	$245.62	$220.86 - $269.43
Q3 2023	81,291	$20,893	$267.47	$251.85 - $287.60
Q2 2023	111,498	$31,760	$297.86	$273.39 - $319.76
Q1 2023	98,821	$27,475	$276.70	$254.80 - $295.90
Q4 2022	93,373	$25,857	$282.44	$250.31 - $311.88
Q3 2022	92,993	$24,829	$212.38	$193.65 - $283.44
Q2 2022	121,162	$24,710	$204.43	$187.16 - $225.50
Q1 2022	128,668	$27,097	$217.46	$192.67 - $249.00
Q4 2021	135,563	$32,524	$257.12	$221.72 - $290.76
Q3 2021	155,112	$43,895	$327.75	$282.64 - $372.12
Q2 2021	291,563	$100,959	$302.94	$257.03 - $468.55
Q1 2021	151,188	$42,295	$269.69	$238.40 - $296.38
Q4 2020	187,435	$45,895	$259.08	$223.25 - $363.92
Q3 2020	118,801	$33,701	$278.91	$261.87 - $312.00
Q2 2020	102,890	$27,528	$300.59	$257.60 - $350.24
Q1 2020	108,329	$34,273	$303.47	$262.25 - $374.99
Q4 2019	155,313	$46,086	$277.46	$219.70 - $318.00
Q3 2019	184,021	$42,844	$232.85	$215.78 - $246.99
Q2 2019	255,076	$59,655	$230.90	$219.20 - $245.35
Q1 2019	292,784	$69,208	$314.89	$216.12 - $344.00
Q4 2018	294,161	$88,519	$319.14	$278.46 - $358.41
Q3 2018	268,851	$94,988	$344.30	$288.13 - $388.67
Q2 2018	356,033	$103,335	$281.15	$249.17 - $310.91
Q1 2018	370,247	$101,381	$310.41	$259.76 - $370.57
Q4 2017	330,865	$105,404	$320.80	$301.81 - $348.84
Q3 2017	348,260	$109,047	$296.11	$269.50 - $330.00
Q2 2017	213,506	$57,937	$264.42	$244.28 - $291.90
Q1 2017	185,796	$50,800	$282.75	$260.50 - $301.42
Q4 2016	252,657	$71,648	$296.43	$268.00 - $329.83
Q3 2016	228,501	$71,528	$296.18	$240.07 - $333.65
Q2 2016	206,741	$49,994	$263.54	$223.02 - $292.69
Q1 2016	172,991	$45,033	$264.15	$242.07 - $301.02
Q4 2015	193,175	$59,179	$287.35	$254.00 - $311.65
Q3 2015	220,265	$64,276	$330.23	$265.00 - $412.24
Q2 2015	193,061	$77,985	$401.33	$368.88 - $432.88
Q1 2015	216,336	$91,346	$394.14	$334.40 - $480.18
Q4 2014	288,766	$98,022	$323.51	$290.85 - $361.93
Q3 2014	227,956	$75,410	$329.72	$298.31 - $349.00
Q2 2014	266,776	$84,117	$300.97	$272.02 - $322.25
Q1 2014	278,319	$85,129	$317.43	$270.62 - $358.89
Q4 2013	263,099	$73,602	$258.65	$221.07 - $298.82
Q3 2013	319,032	$76,810	$223.81	$203.55 - $248.95
Q2 2013	372,572	$80,177	$213.68	$191.80 - $242.64