NASDAQ:BIIB | Historical Stock Price | BIOGEN INC.

Complete retained daily price history on its own workbook tab. Split-adjusted close keeps every historical share price on one comparable split basis. Cumulative dividend-reinvested close is the daily close of a rebased total-return index: it starts with one share at the earliest retained close, reinvests every distribution, and normalizes every forward and reverse split exactly once. Admitted exchange opening prices remain a distinct current-session series.

Available history
1991-09-17 to 2026-09-04
Data captured

Stock Price Chart

Blue: Split-adjusted close · Orange: Cumulative dividend-reinvested close

$0.34$1.42$6.01$25.38$107.26$453.211991-09-172026-08-27

Logarithmic scale. Both lines share the same starting value for the selected range.

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Historical Stock Price — 2020

DateSplit-adjusted closeCumulative dividend-reinvested closeReported volumeOpen priceExchange Volume
2020-12-31$244.86$244.86978,100——
2020-12-30$243.58$243.58750,000——
2020-12-29$243.46$243.461,007,000——
2020-12-28$244.15$244.151,234,200——
2020-12-24$248.89$248.89459,500——
2020-12-23$251.20$251.20972,300——
2020-12-22$247.87$247.87934,600——
2020-12-21$248.32$248.321,279,800——
2020-12-18$249.62$249.623,455,400——
2020-12-17$250.24$250.241,279,000——
2020-12-16$248.19$248.191,154,900——
2020-12-15$248.73$248.731,231,500——
2020-12-14$245.25$245.251,561,000——
2020-12-11$241.43$241.431,140,300——
2020-12-10$242.98$242.981,276,400——
2020-12-09$244.75$244.751,364,600——
2020-12-08$246.43$246.431,228,400——
2020-12-07$243.68$243.681,082,000——
2020-12-04$245.87$245.87961,300——
2020-12-03$244.09$244.09897,100——
2020-12-02$246.92$246.921,317,000——
2020-12-01$243.16$243.161,164,200——
2020-11-30$240.17$240.172,193,500——
2020-11-27$243.78$243.78699,200——
2020-11-25$241.75$241.751,122,400——
2020-11-24$242.51$242.511,605,800——
2020-11-23$243.38$243.381,251,200——
2020-11-20$244.15$244.151,334,800——
2020-11-19$244.01$244.011,222,000——
2020-11-18$240.98$240.981,829,100——
2020-11-17$248.81$248.811,371,600——
2020-11-16$250.96$250.961,607,200——
2020-11-13$248.59$248.591,697,600——
2020-11-12$241.55$241.551,586,800——
2020-11-11$244.03$244.032,332,100——
2020-11-10$236.34$236.343,224,100——
2020-11-09$236.26$236.269,252,600——
2020-11-06$328.90$328.90600——
2020-11-05$328.90$328.905,070,300——
2020-11-04$355.63$355.6314,591,500——
2020-11-03$247.01$247.011,449,800——
2020-11-02$248.99$248.991,469,500——
2020-10-30$252.07$252.071,413,500——
2020-10-29$245.48$245.481,223,300——
2020-10-28$244.26$244.261,647,700——
2020-10-27$255.30$255.301,105,400——
2020-10-26$256.76$256.761,241,000——
2020-10-23$265.00$265.001,016,200——
2020-10-22$266.80$266.801,280,300——
2020-10-21$268.91$268.911,848,600——
2020-10-20$267.12$267.121,155,400——
2020-10-19$268.77$268.771,207,900——
2020-10-16$280.01$280.01843,100——
2020-10-15$280.63$280.63852,900——
2020-10-14$289.02$289.02976,400——
2020-10-13$291.46$291.46683,000——
2020-10-12$291.48$291.481,130,100——
2020-10-09$286.54$286.54946,300——
2020-10-08$286.92$286.92504,300——
2020-10-07$285.75$285.75646,500——
2020-10-06$281.15$281.15758,100——
2020-10-05$284.18$284.18888,000——
2020-10-02$277.64$277.64976,000——
2020-10-01$285.57$285.57971,600——
2020-09-30$283.68$283.681,200,000——
2020-09-29$282.35$282.35864,800——
2020-09-28$282.04$282.041,782,100——
2020-09-25$273.28$273.28737,500——
2020-09-24$270.04$270.04761,800——
2020-09-23$272.20$272.20982,900——
2020-09-22$272.76$272.761,050,000——
2020-09-21$268.30$268.301,733,200——
2020-09-18$274.48$274.483,069,200——
2020-09-17$275.37$275.37972,600——
2020-09-16$276.39$276.391,550,700——
2020-09-15$278.45$278.451,105,400——
2020-09-14$278.29$278.291,102,400——
2020-09-11$269.91$269.91846,100——
2020-09-10$266.51$266.511,095,600——
2020-09-09$272.51$272.51960,900——
2020-09-08$268.90$268.901,246,500——
2020-09-04$276.00$276.001,240,700——
2020-09-03$276.15$276.151,402,600——
2020-09-02$285.60$285.601,040,700——
2020-09-01$279.75$279.751,254,300——
2020-08-31$287.64$287.641,639,500——
2020-08-28$281.46$281.46814,200——
2020-08-27$279.26$279.261,503,200——
2020-08-26$279.17$279.17917,800——
2020-08-25$279.03$279.031,294,700——
2020-08-24$276.56$276.561,006,400——
2020-08-21$277.07$277.07927,300——
2020-08-20$277.52$277.52957,200——
2020-08-19$279.98$279.981,542,400——
2020-08-18$288.88$288.881,029,300——
2020-08-17$289.16$289.161,066,300——
2020-08-14$289.45$289.45619,200——
2020-08-13$288.54$288.54905,300——
2020-08-12$293.22$293.221,016,400——
2020-08-11$289.94$289.941,443,900——
2020-08-10$300.26$300.261,525,000——
2020-08-07$305.71$305.714,454,600——
2020-08-06$277.66$277.66756,500——
2020-08-05$276.17$276.17903,100——
2020-08-04$276.08$276.081,101,000——
2020-08-03$278.16$278.16976,400——
2020-07-31$274.69$274.691,289,700——
2020-07-30$274.86$274.86723,200——
2020-07-29$277.36$277.36816,600——
2020-07-28$280.35$280.351,158,900——
2020-07-27$286.19$286.191,968,100——
2020-07-24$272.33$272.33862,300——
2020-07-23$278.51$278.51948,000——
2020-07-22$280.81$280.811,392,100——
2020-07-21$280.19$280.19888,500——
2020-07-20$283.40$283.40739,700——
2020-07-17$281.88$281.88903,600——
2020-07-16$279.54$279.54944,300——
2020-07-15$282.96$282.961,136,600——
2020-07-14$281.27$281.27895,700——
2020-07-13$276.52$276.521,209,800——
2020-07-10$278.88$278.88955,300——
2020-07-09$278.70$278.701,115,600——
2020-07-08$280.19$280.193,257,800——
2020-07-07$268.35$268.352,069,800——
2020-07-06$269.80$269.80859,400——
2020-07-02$265.12$265.12942,900——
2020-07-01$264.77$264.771,093,800——
2020-06-30$267.55$267.551,274,000——
2020-06-29$260.35$260.35899,300——
2020-06-26$258.66$258.662,356,900——
2020-06-25$262.63$262.631,271,400——
2020-06-24$263.04$263.041,448,800——
2020-06-23$268.19$268.191,820,100——
2020-06-22$264.29$264.292,195,100——
2020-06-19$271.00$271.007,723,100——
2020-06-18$260.30$260.306,575,000——
2020-06-17$281.46$281.462,070,600——
2020-06-16$282.12$282.121,752,900——
2020-06-15$278.49$278.492,187,800——
2020-06-12$279.27$279.272,041,100——
2020-06-11$283.22$283.221,669,500——
2020-06-10$295.25$295.251,430,800——
2020-06-09$293.74$293.742,045,800——
2020-06-08$301.26$301.261,491,000——
2020-06-05$306.72$306.721,297,400——
2020-06-04$299.65$299.651,019,000——
2020-06-03$302.60$302.60945,500——
2020-06-02$302.86$302.86945,800——
2020-06-01$301.45$301.45863,000——
2020-05-29$307.09$307.091,917,300——
2020-05-28$300.50$300.501,431,000——
2020-05-27$301.46$301.461,374,700——
2020-05-26$295.87$295.871,663,500——
2020-05-22$304.53$304.53690,100——
2020-05-21$304.46$304.461,099,700——
2020-05-20$309.53$309.53904,100——
2020-05-19$310.08$310.08862,100——
2020-05-18$315.90$315.901,022,400——
2020-05-15$316.60$316.60820,900——
2020-05-14$315.82$315.821,167,100——
2020-05-13$314.96$314.961,795,900——
2020-05-12$319.77$319.771,882,100——
2020-05-11$328.01$328.011,513,500——
2020-05-08$314.02$314.021,126,200——
2020-05-07$314.01$314.011,764,300——
2020-05-06$306.78$306.781,255,500——
2020-05-05$304.44$304.441,348,400——
2020-05-04$296.52$296.521,253,100——
2020-05-01$293.09$293.091,538,700——
2020-04-30$296.83$296.832,291,100——
2020-04-29$304.71$304.712,100,100——
2020-04-28$305.22$305.221,862,600——
2020-04-27$303.24$303.241,611,400——
2020-04-24$297.80$297.801,778,800——
2020-04-23$292.25$292.252,911,100——
2020-04-22$298.01$298.016,650,100——
2020-04-21$329.01$329.011,521,800——
2020-04-20$339.41$339.411,620,700——
2020-04-17$342.55$342.551,701,800——
2020-04-16$338.34$338.341,602,600——
2020-04-15$326.94$326.941,426,400——
2020-04-14$333.76$333.761,675,500——
2020-04-13$322.94$322.942,083,700——
2020-04-09$321.05$321.051,479,600——
2020-04-08$316.95$316.951,932,300——
2020-04-07$301.21$301.212,457,700——
2020-04-06$311.39$311.393,181,100——
2020-04-03$300.51$300.511,422,800——
2020-04-02$304.47$304.473,286,600——
2020-04-01$293.27$293.272,177,500——
2020-03-31$316.38$316.382,869,100——
2020-03-30$316.13$316.131,747,300——
2020-03-27$296.75$296.751,653,100——
2020-03-26$304.94$304.942,270,100——
2020-03-25$284.98$284.982,678,900——
2020-03-24$276.19$276.193,464,100——
2020-03-23$269.19$269.192,695,400——
2020-03-20$278.77$278.772,730,000——
2020-03-19$288.02$288.022,470,000——
2020-03-18$298.68$298.682,767,300——
2020-03-17$305.32$305.322,625,900——
2020-03-16$281.72$281.723,862,600——
2020-03-13$305.21$305.213,641,100——
2020-03-12$268.88$268.882,901,000——
2020-03-11$294.25$294.251,878,900——
2020-03-10$305.63$305.632,378,600——
2020-03-09$297.19$297.192,149,500——
2020-03-06$317.95$317.951,513,000——
2020-03-05$317.70$317.701,470,400——
2020-03-04$328.45$328.451,752,300——
2020-03-03$315.78$315.782,036,100——
2020-03-02$327.89$327.892,364,600——
2020-02-28$308.39$308.392,396,200——
2020-02-27$310.08$310.082,221,100——
2020-02-26$327.45$327.451,411,300——
2020-02-25$324.11$324.111,831,100——
2020-02-24$325.98$325.981,732,500——
2020-02-21$336.71$336.71923,200——
2020-02-20$336.64$336.641,497,800——
2020-02-19$341.04$341.041,488,400——
2020-02-18$337.10$337.101,515,100——
2020-02-14$333.00$333.001,023,200——
2020-02-13$334.25$334.251,307,300——
2020-02-12$331.76$331.761,603,000——
2020-02-11$332.29$332.291,806,200——
2020-02-10$338.93$338.931,867,000——
2020-02-07$338.70$338.702,209,400——
2020-02-06$337.24$337.243,613,600——
2020-02-05$332.87$332.8710,159,200——
2020-02-04$283.29$283.291,684,400——
2020-02-03$272.73$272.731,257,800——
2020-01-31$268.85$268.851,701,700——
2020-01-30$277.53$277.531,601,000——
2020-01-29$282.52$282.521,166,200——
2020-01-28$281.95$281.951,136,500——
2020-01-27$281.14$281.141,405,500——
2020-01-24$278.14$278.141,260,200——
2020-01-23$284.21$284.211,936,100——
2020-01-22$288.10$288.101,571,000——
2020-01-21$287.19$287.192,253,100——
2020-01-17$285.50$285.501,765,000——
2020-01-16$286.14$286.142,800,000——
2020-01-15$293.09$293.091,975,600——
2020-01-14$298.97$298.972,112,600——
2020-01-13$293.90$293.901,401,100——
2020-01-10$296.51$296.511,164,500——
2020-01-09$294.30$294.30966,500——
2020-01-08$292.66$292.661,059,000——
2020-01-07$290.09$290.091,034,000——
2020-01-06$290.82$290.821,271,000——
2020-01-03$290.85$290.85700,100——
2020-01-02$294.24$294.241,178,300——