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 — 1998

DateSplit-adjusted closeCumulative dividend-reinvested closeReported volumeOpen priceExchange Volume
1998-12-31$7.83$7.831,443,600
1998-12-30$7.65$7.651,081,800
1998-12-29$7.58$7.581,131,600
1998-12-28$7.33$7.331,798,800
1998-12-24$7.27$7.27985,800
1998-12-23$7.35$7.358,590,200
1998-12-22$7.80$7.801,656,600
1998-12-21$7.72$7.724,709,400
1998-12-18$8.02$8.024,896,000
1998-12-17$7.52$7.525,211,600
1998-12-16$7.50$7.505,724,000
1998-12-15$7.03$7.034,747,200
1998-12-14$6.90$6.905,598,000
1998-12-11$7.26$7.2612,088,200
1998-12-10$6.44$6.444,602,000
1998-12-09$6.08$6.083,603,000
1998-12-08$6.02$6.025,090,400
1998-12-07$5.60$5.603,154,800
1998-12-04$5.52$5.523,370,800
1998-12-03$5.54$5.546,912,000
1998-12-02$5.25$5.258,884,200
1998-12-01$5.15$5.1511,610,600
1998-11-30$5.60$5.602,905,800
1998-11-27$5.54$5.54946,200
1998-11-25$5.56$5.561,389,000
1998-11-24$5.46$5.461,155,600
1998-11-23$5.42$5.421,887,000
1998-11-20$5.40$5.401,677,000
1998-11-19$5.13$5.13942,600
1998-11-18$4.99$4.991,330,200
1998-11-17$4.92$4.921,389,000
1998-11-16$4.96$4.961,617,000
1998-11-13$5.25$5.25780,000
1998-11-12$5.29$5.29591,600
1998-11-11$5.24$5.24600,600
1998-11-10$5.08$5.081,357,800
1998-11-09$5.08$5.082,325,000
1998-11-06$5.50$5.502,265,600
1998-11-05$5.33$5.331,500,600
1998-11-04$5.17$5.171,718,400
1998-11-03$5.03$5.03952,800
1998-11-02$5.15$5.152,529,000
1998-10-30$4.98$4.984,935,000
1998-10-29$4.98$4.983,656,400
1998-10-28$4.48$4.481,282,800
1998-10-27$4.52$4.521,335,000
1998-10-26$4.91$4.911,952,400
1998-10-23$4.59$4.59744,000
1998-10-22$4.60$4.601,334,400
1998-10-21$4.46$4.462,801,400
1998-10-20$4.38$4.3811,620,200
1998-10-19$4.46$4.463,030,600
1998-10-16$4.11$4.112,158,800
1998-10-15$4.00$4.002,508,000
1998-10-14$3.78$3.784,957,800
1998-10-13$3.67$3.671,105,800
1998-10-12$3.76$3.762,330,400
1998-10-09$3.38$3.382,977,800
1998-10-08$3.21$3.213,940,200
1998-10-07$3.52$3.521,369,200
1998-10-06$3.63$3.631,165,800
1998-10-05$3.83$3.832,199,600
1998-10-02$4.00$4.001,791,600
1998-10-01$3.82$3.82879,600
1998-09-30$3.96$3.961,456,200
1998-09-29$3.88$3.883,160,800
1998-09-28$4.10$4.103,090,000
1998-09-25$4.63$4.632,301,000
1998-09-24$4.61$4.612,062,200
1998-09-23$4.65$4.653,871,200
1998-09-22$4.65$4.654,436,400
1998-09-21$4.13$4.13915,600
1998-09-18$4.19$4.19489,000
1998-09-17$4.13$4.13877,800
1998-09-16$4.29$4.291,104,600
1998-09-15$4.25$4.251,977,600
1998-09-14$4.02$4.022,236,800
1998-09-11$4.08$4.083,238,800
1998-09-10$3.81$3.811,720,800
1998-09-09$3.94$3.941,288,200
1998-09-08$4.00$4.002,130,000
1998-09-04$3.60$3.601,726,800
1998-09-03$3.63$3.634,180,200
1998-09-02$3.34$3.346,970,200
1998-09-01$2.92$2.923,354,600
1998-08-31$3.00$3.003,958,800
1998-08-28$3.53$3.531,639,200
1998-08-27$3.58$3.582,888,400
1998-08-26$3.56$3.561,977,000
1998-08-25$3.77$3.771,890,000
1998-08-24$3.83$3.83545,400
1998-08-21$3.85$3.852,296,200
1998-08-20$3.94$3.94889,800
1998-08-19$3.92$3.922,533,800
1998-08-18$4.13$4.132,526,600
1998-08-17$3.83$3.831,399,800
1998-08-14$3.88$3.881,262,400
1998-08-13$3.81$3.813,309,000
1998-08-12$3.92$3.921,418,400
1998-08-11$3.94$3.941,843,800
1998-08-10$4.29$4.291,051,200
1998-08-07$4.30$4.303,505,200
1998-08-06$4.02$4.02854,400
1998-08-05$3.91$3.915,164,200
1998-08-04$3.89$3.895,376,600
1998-08-03$3.72$3.723,215,400
1998-07-31$3.95$3.951,284,000
1998-07-30$4.04$4.04685,200
1998-07-29$3.96$3.962,910,600
1998-07-28$3.91$3.912,767,200
1998-07-27$3.92$3.922,392,800
1998-07-24$4.10$4.101,727,400
1998-07-23$4.22$4.221,725,600
1998-07-22$4.36$4.361,818,600
1998-07-21$4.46$4.463,103,800
1998-07-20$4.35$4.352,998,200
1998-07-17$4.54$4.543,616,200
1998-07-16$4.26$4.262,566,200
1998-07-15$4.44$4.444,277,400
1998-07-14$4.44$4.4415,552,600
1998-07-13$3.83$3.832,679,600
1998-07-10$3.85$3.851,591,200
1998-07-09$3.85$3.853,853,800
1998-07-08$3.76$3.763,182,400
1998-07-07$3.81$3.811,876,200
1998-07-06$3.93$3.931,033,200
1998-07-02$3.82$3.821,758,600
1998-07-01$3.98$3.981,295,400
1998-06-30$3.93$3.934,008,600
1998-06-29$4.25$4.251,510,800
1998-06-26$4.29$4.291,156,800
1998-06-25$4.43$4.432,439,600
1998-06-24$4.46$4.461,272,600
1998-06-23$4.21$4.211,773,000
1998-06-22$4.19$4.192,005,200
1998-06-19$4.27$4.271,736,400
1998-06-18$4.38$4.383,015,000
1998-06-17$4.54$4.543,196,800
1998-06-16$4.73$4.731,617,000
1998-06-15$4.58$4.58865,800
1998-06-12$4.69$4.691,503,600
1998-06-11$4.69$4.693,079,200
1998-06-10$4.75$4.752,773,800
1998-06-09$4.71$4.711,392,600
1998-06-08$4.73$4.735,403,600
1998-06-05$4.54$4.548,658,000
1998-06-04$5.23$5.23779,400
1998-06-03$5.10$5.101,156,800
1998-06-02$5.10$5.101,206,000
1998-06-01$5.15$5.151,387,200
1998-05-29$5.25$5.252,238,000
1998-05-28$5.58$5.582,038,800
1998-05-27$5.29$5.292,715,000
1998-05-26$5.42$5.422,610,600
1998-05-22$5.33$5.333,157,800
1998-05-21$5.25$5.259,592,200
1998-05-20$5.57$5.572,040,000
1998-05-19$5.64$5.643,615,600
1998-05-18$5.79$5.795,482,800
1998-05-15$6.04$6.041,338,600
1998-05-14$6.19$6.192,257,800
1998-05-13$6.00$6.002,801,400
1998-05-12$5.81$5.812,410,200
1998-05-11$5.58$5.581,401,600
1998-05-08$5.81$5.812,740,200
1998-05-07$5.68$5.681,961,400
1998-05-06$5.95$5.951,725,600
1998-05-05$5.90$5.901,924,800
1998-05-04$5.96$5.961,470,000
1998-05-01$6.06$6.06816,600
1998-04-30$6.00$6.003,118,800
1998-04-29$5.79$5.793,153,600
1998-04-28$5.52$5.522,937,600
1998-04-27$5.44$5.443,229,200
1998-04-24$5.65$5.652,745,600
1998-04-23$5.83$5.832,587,800
1998-04-22$5.98$5.982,993,400
1998-04-21$6.02$6.024,123,200
1998-04-20$6.13$6.135,827,200
1998-04-17$6.58$6.582,257,800
1998-04-16$6.52$6.524,105,800
1998-04-15$6.19$6.197,000,200
1998-04-14$6.48$6.488,859,000
1998-04-13$6.82$6.821,527,000
1998-04-09$6.99$6.992,486,400
1998-04-08$6.83$6.833,070,800
1998-04-07$6.96$6.96737,400
1998-04-06$7.04$7.041,037,400
1998-04-03$7.17$7.171,794,600
1998-04-02$7.52$7.521,428,600
1998-04-01$7.44$7.441,346,400
1998-03-31$7.38$7.382,029,800
1998-03-30$7.17$7.171,900,200
1998-03-27$7.28$7.28774,000
1998-03-26$7.41$7.41433,800
1998-03-25$7.44$7.44613,200
1998-03-24$7.52$7.521,986,600
1998-03-23$7.56$7.562,710,200
1998-03-20$7.58$7.58715,800
1998-03-19$7.58$7.58686,400
1998-03-18$7.58$7.58639,000
1998-03-17$7.53$7.531,691,400
1998-03-16$7.42$7.421,035,600
1998-03-13$7.54$7.541,677,600
1998-03-12$7.57$7.572,396,400
1998-03-11$7.48$7.482,331,600
1998-03-10$7.33$7.331,425,000
1998-03-09$7.00$7.002,431,200
1998-03-06$7.21$7.212,011,200
1998-03-05$6.88$6.883,588,000
1998-03-04$6.54$6.544,150,200
1998-03-03$6.85$6.857,417,200
1998-03-02$7.17$7.177,044,600
1998-02-27$7.56$7.562,977,200
1998-02-26$7.33$7.33953,400
1998-02-25$7.25$7.251,308,000
1998-02-24$6.97$6.978,014,200
1998-02-23$7.25$7.25881,400
1998-02-20$7.42$7.42897,000
1998-02-19$7.48$7.481,935,600
1998-02-18$7.48$7.481,461,000
1998-02-17$7.25$7.251,928,400
1998-02-13$7.29$7.291,675,800
1998-02-12$7.08$7.081,593,000
1998-02-11$7.08$7.082,601,600
1998-02-10$7.31$7.312,327,400
1998-02-09$7.23$7.232,728,800
1998-02-06$6.96$6.962,085,000
1998-02-05$6.92$6.923,072,000
1998-02-04$7.08$7.081,193,400
1998-02-03$7.08$7.08922,200
1998-02-02$7.19$7.193,129,000
1998-01-30$6.96$6.962,370,600
1998-01-29$7.15$7.151,966,200
1998-01-28$7.13$7.131,122,600
1998-01-27$6.93$6.931,043,400
1998-01-26$6.83$6.83655,200
1998-01-23$7.00$7.002,783,400
1998-01-22$7.00$7.001,041,000
1998-01-21$7.06$7.062,749,200
1998-01-20$7.21$7.216,522,600
1998-01-16$6.46$6.46969,600
1998-01-15$6.54$6.542,763,000
1998-01-14$6.50$6.505,809,200
1998-01-13$6.23$6.233,450,600
1998-01-12$5.83$5.831,665,600
1998-01-09$5.99$5.991,521,000
1998-01-08$5.88$5.882,120,400
1998-01-07$5.71$5.712,959,800
1998-01-06$5.83$5.831,642,200
1998-01-05$5.67$5.67753,000
1998-01-02$5.65$5.651,328,400