BIOGEN INC

Ticker: BIIB CUSIP: 09062X103 Class: COM

CALIFORNIA PUBLIC EMPLOYEES RETIREMENT SYSTEM's Holding History (CIK: 0000919079)

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

Q4 2025

Shares 330,806 Value ($000) $58,219 Avg Close $163.37 Range $138.00 - $185.17

Q3 2025

Shares 343,786 Value ($000) $48,158 Avg Close $135.17 Range $121.05 - $150.28

Q2 2025

Shares 339,050 Value ($000) $42,581 Avg Close $124.60 Range $110.04 - $137.32

Q1 2025

Shares 385,094 Value ($000) $52,696 Avg Close $142.96 Range $128.51 - $157.09

Q4 2024

Shares 397,849 Value ($000) $60,839 Avg Close $168.67 Range $145.07 - $195.00

Q3 2024

Shares 395,071 Value ($000) $76,581 Avg Close $209.21 Range $188.78 - $238.00

Q2 2024

Shares 396,065 Value ($000) $91,816 Avg Close $217.32 Range $189.44 - $237.54

Q1 2024

Shares 404,419 Value ($000) $87,205 Avg Close $234.20 Range $211.02 - $268.30

Q4 2023

Shares 363,209 Value ($000) $93,988 Avg Close $245.62 Range $220.86 - $269.43

Q3 2023

Shares 281,163 Value ($000) $72,262 Avg Close $267.47 Range $251.85 - $287.60

Q2 2023

Shares 274,631 Value ($000) $78,229 Avg Close $297.86 Range $273.39 - $319.76

Q1 2023

Shares 309,617 Value ($000) $86,083 Avg Close $276.70 Range $254.80 - $295.90

Q4 2022

Shares 371,892 Value ($000) $102,984 Avg Close $282.44 Range $250.31 - $311.88

Q3 2022

Shares 385,993 Value ($000) $103,060 Avg Close $212.38 Range $193.65 - $283.44

Q2 2022

Shares 371,897 Value ($000) $75,845 Avg Close $204.43 Range $187.16 - $225.50

Q1 2022

Shares 426,356 Value ($000) $89,791 Avg Close $217.46 Range $192.67 - $249.00

Q4 2021

Shares 450,741 Value ($000) $108,142 Avg Close $257.12 Range $221.72 - $290.76

Q3 2021

Shares 468,268 Value ($000) $132,515 Avg Close $327.75 Range $282.64 - $372.12

Q2 2021

Shares 473,506 Value ($000) $163,961 Avg Close $302.94 Range $257.03 - $468.55

Q1 2021

Shares 372,703 Value ($000) $104,264 Avg Close $269.69 Range $238.40 - $296.38

Q4 2020

Shares 387,722 Value ($000) $94,938 Avg Close $259.08 Range $223.25 - $363.92

Q3 2020

Shares 379,347 Value ($000) $107,613 Avg Close $278.91 Range $261.87 - $312.00

Q2 2020

Shares 378,360 Value ($000) $101,230 Avg Close $300.59 Range $257.60 - $350.24

Q1 2020

Shares 402,289 Value ($000) $127,276 Avg Close $303.47 Range $262.25 - $374.99

Q4 2019

Shares 454,203 Value ($000) $134,776 Avg Close $277.46 Range $219.70 - $318.00

Q3 2019

Shares 495,531 Value ($000) $115,370 Avg Close $232.85 Range $215.78 - $246.99

Q2 2019

Shares 456,394 Value ($000) $106,737 Avg Close $230.90 Range $219.20 - $245.35

Q1 2019

Shares 481,673 Value ($000) $113,858 Avg Close $314.89 Range $216.12 - $344.00

Q4 2018

Shares 479,928 Value ($000) $144,420 Avg Close $319.14 Range $278.46 - $358.41

Q3 2018

Shares 509,897 Value ($000) $180,152 Avg Close $344.30 Range $288.13 - $388.67

Q2 2018

Shares 548,675 Value ($000) $159,247 Avg Close $281.15 Range $249.17 - $310.91

Q1 2018

Shares 548,135 Value ($000) $150,090 Avg Close $310.41 Range $259.76 - $370.57

Q4 2017

Shares 532,236 Value ($000) $169,554 Avg Close $320.80 Range $301.81 - $348.84

Q3 2017

Shares 503,518 Value ($000) $157,662 Avg Close $296.11 Range $269.50 - $330.00

Q2 2017

Shares 498,300 Value ($000) $135,219 Avg Close $264.42 Range $244.28 - $291.90

Q1 2017

Shares 490,700 Value ($000) $134,167 Avg Close $282.75 Range $260.50 - $301.42

Q4 2016

Shares 473,100 Value ($000) $134,162 Avg Close $296.43 Range $268.00 - $329.83

Q3 2016

Shares 532,800 Value ($000) $166,782 Avg Close $296.18 Range $240.07 - $333.65

Q2 2016

Shares 548,700 Value ($000) $132,687 Avg Close $263.54 Range $223.02 - $292.69

Q1 2016

Shares 563,300 Value ($000) $146,638 Avg Close $264.15 Range $242.07 - $301.02

Q4 2015

Shares 608,000 Value ($000) $186,261 Avg Close $287.35 Range $254.00 - $311.65

Q3 2015

Shares 610,699 Value ($000) $178,208 Avg Close $330.23 Range $265.00 - $412.24

Q2 2015

Shares 610,399 Value ($000) $246,565 Avg Close $401.33 Range $368.88 - $432.88

Q1 2015

Shares 741,610 Value ($000) $265,415 Avg Close $394.14 Range $334.40 - $480.18

Q4 2014

Shares 741,610 Value ($000) $265,415 Avg Close $323.51 Range $290.85 - $361.93

Q3 2014

Shares 821,392 Value ($000) $271,725 Avg Close $329.72 Range $298.31 - $349.00

Q2 2014

Shares 783,057 Value ($000) $246,906 Avg Close $300.97 Range $272.02 - $322.25

Q1 2014

Shares 821,756 Value ($000) $234,956 Avg Close $317.43 Range $270.62 - $358.89

Q4 2013

Shares 796,482 Value ($000) $224,082 Avg Close $258.65 Range $221.07 - $298.82

Q3 2013

Shares 594,768 Value ($000) $143,196 Avg Close $223.81 Range $203.55 - $248.95

Q2 2013

Shares 589,213 Value ($000) $126,799 Avg Close $213.68 Range $191.80 - $242.64

Period	Shares	Value ($000)	Average Close	Price Range
Q4 2025	330,806	$58,219	$163.37	$138.00 - $185.17
Q3 2025	343,786	$48,158	$135.17	$121.05 - $150.28
Q2 2025	339,050	$42,581	$124.60	$110.04 - $137.32
Q1 2025	385,094	$52,696	$142.96	$128.51 - $157.09
Q4 2024	397,849	$60,839	$168.67	$145.07 - $195.00
Q3 2024	395,071	$76,581	$209.21	$188.78 - $238.00
Q2 2024	396,065	$91,816	$217.32	$189.44 - $237.54
Q1 2024	404,419	$87,205	$234.20	$211.02 - $268.30
Q4 2023	363,209	$93,988	$245.62	$220.86 - $269.43
Q3 2023	281,163	$72,262	$267.47	$251.85 - $287.60
Q2 2023	274,631	$78,229	$297.86	$273.39 - $319.76
Q1 2023	309,617	$86,083	$276.70	$254.80 - $295.90
Q4 2022	371,892	$102,984	$282.44	$250.31 - $311.88
Q3 2022	385,993	$103,060	$212.38	$193.65 - $283.44
Q2 2022	371,897	$75,845	$204.43	$187.16 - $225.50
Q1 2022	426,356	$89,791	$217.46	$192.67 - $249.00
Q4 2021	450,741	$108,142	$257.12	$221.72 - $290.76
Q3 2021	468,268	$132,515	$327.75	$282.64 - $372.12
Q2 2021	473,506	$163,961	$302.94	$257.03 - $468.55
Q1 2021	372,703	$104,264	$269.69	$238.40 - $296.38
Q4 2020	387,722	$94,938	$259.08	$223.25 - $363.92
Q3 2020	379,347	$107,613	$278.91	$261.87 - $312.00
Q2 2020	378,360	$101,230	$300.59	$257.60 - $350.24
Q1 2020	402,289	$127,276	$303.47	$262.25 - $374.99
Q4 2019	454,203	$134,776	$277.46	$219.70 - $318.00
Q3 2019	495,531	$115,370	$232.85	$215.78 - $246.99
Q2 2019	456,394	$106,737	$230.90	$219.20 - $245.35
Q1 2019	481,673	$113,858	$314.89	$216.12 - $344.00
Q4 2018	479,928	$144,420	$319.14	$278.46 - $358.41
Q3 2018	509,897	$180,152	$344.30	$288.13 - $388.67
Q2 2018	548,675	$159,247	$281.15	$249.17 - $310.91
Q1 2018	548,135	$150,090	$310.41	$259.76 - $370.57
Q4 2017	532,236	$169,554	$320.80	$301.81 - $348.84
Q3 2017	503,518	$157,662	$296.11	$269.50 - $330.00
Q2 2017	498,300	$135,219	$264.42	$244.28 - $291.90
Q1 2017	490,700	$134,167	$282.75	$260.50 - $301.42
Q4 2016	473,100	$134,162	$296.43	$268.00 - $329.83
Q3 2016	532,800	$166,782	$296.18	$240.07 - $333.65
Q2 2016	548,700	$132,687	$263.54	$223.02 - $292.69
Q1 2016	563,300	$146,638	$264.15	$242.07 - $301.02
Q4 2015	608,000	$186,261	$287.35	$254.00 - $311.65
Q3 2015	610,699	$178,208	$330.23	$265.00 - $412.24
Q2 2015	610,399	$246,565	$401.33	$368.88 - $432.88
Q1 2015	741,610	$265,415	$394.14	$334.40 - $480.18
Q4 2014	741,610	$265,415	$323.51	$290.85 - $361.93
Q3 2014	821,392	$271,725	$329.72	$298.31 - $349.00
Q2 2014	783,057	$246,906	$300.97	$272.02 - $322.25
Q1 2014	821,756	$234,956	$317.43	$270.62 - $358.89
Q4 2013	796,482	$224,082	$258.65	$221.07 - $298.82
Q3 2013	594,768	$143,196	$223.81	$203.55 - $248.95
Q2 2013	589,213	$126,799	$213.68	$191.80 - $242.64