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 — 2001

DateSplit-adjusted closeCumulative dividend-reinvested closeReported volumeOpen priceExchange Volume
2001-12-31$68.93$68.931,989,500
2001-12-28$72.23$72.231,893,000
2001-12-27$70.25$70.251,259,800
2001-12-26$70.43$70.431,112,000
2001-12-24$69.57$69.57786,800
2001-12-21$68.28$68.282,869,100
2001-12-20$67.60$67.602,516,600
2001-12-19$69.94$69.943,413,400
2001-12-18$71.16$71.162,424,100
2001-12-17$70.99$70.994,052,800
2001-12-14$67.70$67.707,026,100
2001-12-13$67.41$67.412,787,100
2001-12-12$67.29$67.294,253,000
2001-12-11$67.75$67.754,672,700
2001-12-10$64.81$64.815,033,500
2001-12-07$68.75$68.752,903,300
2001-12-06$71.15$71.152,517,300
2001-12-05$70.76$70.763,695,800
2001-12-04$69.43$69.433,594,500
2001-12-03$69.26$69.263,136,600
2001-11-30$70.30$70.303,333,200
2001-11-29$69.21$69.213,395,400
2001-11-28$67.23$67.233,676,400
2001-11-27$69.67$69.672,716,500
2001-11-26$70.31$70.313,402,800
2001-11-23$67.00$67.001,036,100
2001-11-21$66.97$66.973,047,200
2001-11-20$67.47$67.472,731,200
2001-11-19$70.54$70.543,080,500
2001-11-16$67.61$67.611,506,500
2001-11-15$67.33$67.331,825,800
2001-11-14$67.18$67.182,206,600
2001-11-13$67.60$67.603,607,200
2001-11-12$64.25$64.252,223,000
2001-11-09$62.71$62.712,076,300
2001-11-08$63.11$63.113,151,800
2001-11-07$64.83$64.833,353,900
2001-11-06$65.51$65.513,931,500
2001-11-05$63.92$63.923,349,900
2001-11-02$61.20$61.202,745,900
2001-11-01$61.20$61.202,172,300
2001-10-31$59.98$59.984,204,600
2001-10-30$59.21$59.213,466,700
2001-10-29$56.89$56.892,452,200
2001-10-26$60.55$60.552,490,700
2001-10-25$59.86$59.862,770,900
2001-10-24$57.05$57.052,181,800
2001-10-23$57.12$57.122,839,700
2001-10-22$57.23$57.232,748,500
2001-10-19$55.00$55.003,049,200
2001-10-18$53.39$53.392,248,500
2001-10-17$51.91$51.912,205,200
2001-10-16$53.94$53.942,028,500
2001-10-15$53.49$53.491,960,200
2001-10-12$52.93$52.933,764,000
2001-10-11$52.97$52.978,527,900
2001-10-10$50.07$50.078,581,300
2001-10-09$50.33$50.332,725,100
2001-10-08$48.82$48.822,010,900
2001-10-05$50.62$50.622,632,700
2001-10-04$51.47$51.475,371,600
2001-10-03$53.74$53.743,296,200
2001-10-02$51.62$51.622,969,700
2001-10-01$51.60$51.603,804,000
2001-09-28$49.57$49.574,259,100
2001-09-27$51.27$51.273,521,500
2001-09-26$46.36$46.363,190,300
2001-09-25$46.06$46.064,060,800
2001-09-24$45.34$45.344,294,000
2001-09-21$46.58$46.585,953,100
2001-09-20$50.09$50.094,305,600
2001-09-19$49.81$49.815,972,400
2001-09-18$50.31$50.313,427,200
2001-09-17$53.94$53.946,109,700
2001-09-10$56.15$56.158,436,600
2001-09-07$57.61$57.613,538,800
2001-09-06$56.70$56.703,469,400
2001-09-05$58.56$58.563,649,400
2001-09-04$59.27$59.273,628,000
2001-08-31$59.27$59.272,327,100
2001-08-30$60.42$60.422,786,700
2001-08-29$60.04$60.042,902,600
2001-08-28$59.91$59.912,839,000
2001-08-27$60.34$60.343,022,400
2001-08-24$60.92$60.925,001,200
2001-08-23$57.37$57.3710,206,800
2001-08-22$52.89$52.892,851,100
2001-08-21$50.11$50.111,856,100
2001-08-20$49.93$49.931,439,400
2001-08-17$50.31$50.311,651,800
2001-08-16$51.53$51.532,179,400
2001-08-15$50.82$50.823,032,300
2001-08-14$52.24$52.242,583,800
2001-08-13$50.77$50.772,255,300
2001-08-10$48.62$48.624,428,700
2001-08-09$48.29$48.292,971,400
2001-08-08$47.14$47.144,060,000
2001-08-07$47.96$47.963,043,400
2001-08-06$49.34$49.342,389,400
2001-08-03$50.41$50.413,544,600
2001-08-02$49.69$49.694,471,200
2001-08-01$51.05$51.054,310,100
2001-07-31$53.98$53.982,346,700
2001-07-30$55.79$55.791,298,900
2001-07-27$56.90$56.902,249,600
2001-07-26$55.12$55.122,673,900
2001-07-25$52.93$52.933,484,900
2001-07-24$53.96$53.963,311,200
2001-07-23$55.04$55.043,615,800
2001-07-20$52.98$52.982,962,000
2001-07-19$51.60$51.602,743,600
2001-07-18$52.77$52.772,673,200
2001-07-17$52.15$52.153,478,200
2001-07-16$49.99$49.994,076,800
2001-07-13$54.77$54.774,189,100
2001-07-12$52.16$52.1617,803,100
2001-07-11$61.48$61.484,905,300
2001-07-10$61.30$61.303,986,300
2001-07-09$63.78$63.782,469,100
2001-07-06$61.77$61.774,072,900
2001-07-05$63.60$63.603,319,400
2001-07-03$68.03$68.032,802,300
2001-07-02$65.75$65.753,348,900
2001-06-29$67.69$67.694,874,100
2001-06-28$64.98$64.984,875,900
2001-06-27$64.38$64.385,949,900
2001-06-26$62.84$62.842,999,200
2001-06-25$65.09$65.093,346,500
2001-06-22$66.73$66.733,208,300
2001-06-21$68.61$68.614,439,200
2001-06-20$70.84$70.844,899,600
2001-06-19$70.00$70.003,253,200
2001-06-18$71.47$71.473,201,500
2001-06-15$73.00$73.004,069,600
2001-06-14$70.35$70.353,672,300
2001-06-13$68.50$68.504,869,400
2001-06-12$67.97$67.973,668,200
2001-06-11$68.94$68.943,342,300
2001-06-08$71.66$71.662,087,400
2001-06-07$72.96$72.962,946,400
2001-06-06$70.96$70.965,827,800
2001-06-05$74.57$74.577,059,300
2001-06-04$68.96$68.964,186,300
2001-06-01$65.39$65.392,547,200
2001-05-31$61.60$61.603,621,000
2001-05-30$59.85$59.853,448,500
2001-05-29$60.42$60.421,999,200
2001-05-25$60.53$60.531,592,500
2001-05-24$60.42$60.423,089,200
2001-05-23$57.17$57.172,351,000
2001-05-22$60.20$60.203,686,300
2001-05-21$62.45$62.454,952,000
2001-05-18$57.05$57.053,832,100
2001-05-17$55.10$55.103,952,400
2001-05-16$53.18$53.184,023,500
2001-05-15$49.81$49.813,089,000
2001-05-14$50.64$50.642,306,700
2001-05-11$52.00$52.003,812,000
2001-05-10$52.81$52.812,339,400
2001-05-09$54.19$54.192,020,600
2001-05-08$55.02$55.023,471,400
2001-05-07$52.96$52.964,115,900
2001-05-04$51.94$51.948,696,200
2001-05-03$45.10$45.102,703,900
2001-05-02$46.54$46.543,085,700
2001-05-01$47.51$47.514,129,000
2001-04-30$49.20$49.204,564,000
2001-04-27$48.03$48.032,222,900
2001-04-26$45.10$45.102,624,800
2001-04-25$46.06$46.062,857,600
2001-04-24$43.09$43.093,230,200
2001-04-23$44.88$44.883,139,900
2001-04-20$48.27$48.279,117,000
2001-04-19$52.14$52.144,603,100
2001-04-18$54.65$54.656,274,300
2001-04-17$50.51$50.514,784,800
2001-04-16$48.78$48.783,711,200
2001-04-12$49.23$49.232,716,900
2001-04-11$45.37$45.374,121,600
2001-04-10$47.31$47.313,008,600
2001-04-09$43.39$43.392,602,000
2001-04-06$41.38$41.384,386,100
2001-04-05$42.13$42.134,594,600
2001-04-04$35.75$35.754,858,700
2001-04-03$35.69$35.695,892,600
2001-04-02$38.69$38.694,249,100
2001-03-30$40.00$40.003,399,300
2001-03-29$41.00$41.004,758,700
2001-03-28$39.38$39.383,207,000
2001-03-27$38.44$38.445,041,000
2001-03-26$39.06$39.064,419,600
2001-03-23$39.69$39.696,289,000
2001-03-22$38.56$38.5612,179,800
2001-03-21$42.06$42.065,447,800
2001-03-20$49.13$49.132,531,300
2001-03-19$52.50$52.503,102,700
2001-03-16$48.13$48.134,464,400
2001-03-15$50.94$50.942,543,700
2001-03-14$51.13$51.135,110,000
2001-03-13$48.00$48.003,577,200
2001-03-12$45.69$45.693,138,700
2001-03-09$51.13$51.132,267,800
2001-03-08$55.63$55.632,330,500
2001-03-07$56.06$56.062,094,400
2001-03-06$57.00$57.004,673,600
2001-03-05$54.94$54.942,225,700
2001-03-02$54.31$54.312,695,200
2001-03-01$54.55$54.552,400,300
2001-02-28$56.38$56.381,715,100
2001-02-27$54.44$54.442,097,200
2001-02-26$58.00$58.003,717,000
2001-02-23$54.00$54.003,342,400
2001-02-22$52.56$52.562,879,100
2001-02-21$53.25$53.252,341,600
2001-02-20$55.50$55.502,817,200
2001-02-16$55.00$55.003,736,300
2001-02-15$59.50$59.502,471,400
2001-02-14$60.44$60.442,076,200
2001-02-13$59.63$59.632,271,200
2001-02-12$61.75$61.752,534,600
2001-02-09$59.31$59.311,738,100
2001-02-08$59.50$59.501,752,000
2001-02-07$58.13$58.132,785,700
2001-02-06$59.00$59.002,211,000
2001-02-05$57.50$57.502,038,000
2001-02-02$57.23$57.234,011,200
2001-02-01$57.06$57.062,225,200
2001-01-31$58.81$58.812,834,200
2001-01-30$62.63$62.633,605,800
2001-01-29$66.81$66.813,500,300
2001-01-26$63.31$63.311,765,300
2001-01-25$61.77$61.771,780,900
2001-01-24$64.06$64.064,861,400
2001-01-23$63.13$63.133,419,300
2001-01-22$60.13$60.133,578,100
2001-01-19$56.89$56.893,840,900
2001-01-18$56.88$56.883,473,300
2001-01-17$54.44$54.446,144,300
2001-01-16$57.33$57.333,551,100
2001-01-12$56.21$56.218,835,000
2001-01-11$55.00$55.006,415,500
2001-01-10$52.71$52.719,818,700
2001-01-09$47.83$47.838,837,400
2001-01-08$49.73$49.7311,867,100
2001-01-05$51.69$51.697,761,900
2001-01-04$55.33$55.338,531,700
2001-01-03$62.10$62.1012,440,700
2001-01-02$59.25$59.255,691,300