Biogen Inc. (BIIB) stock
BIIBNasdaqBiological Products, (No Diagnostic Substances)Fiscal year ends December 31
Financials through Q2 FY2026, quarter ended Jun 30, 2026Last filing: 10-Q on Oct 28, 2026Score 4/3061% above fair value
$253.62+3.97 (+1.59%)
Close on Oct 30, 2026Market cap $37.47BP/E 44.9Yield –
Price history
Biogen share prices for every trading day, newest first. Adjusted for stock splits, not for dividends.
Close, Oct 30, 2026
$253.62
+1.59% on the day
52-week range
$138.00 – $258.78
-2.0% from the high
Change over 52 weeks
+69.5%
From $149.61 on Oct 30, 2025
Average volume
1.16M
Shares a day, last 90 sessions
| Date | Open | High | Low | Close | Change | Volume |
|---|---|---|---|---|---|---|
| Oct 30, 2026 | $255.39 | $258.73 | $251.19 | $253.62 | +1.59% | 1,303,306 |
| Oct 29, 2026 | $250.15 | $255.55 | $246.48 | $249.65 | +2.29% | 1,157,854 |
| Oct 28, 2026 | $244.93 | $258.78 | $243.03 | $244.05 | -3.43% | 2,493,008 |
| Oct 27, 2026 | $250.35 | $253.98 | $248.46 | $252.73 | +0.19% | 1,393,391 |
| Oct 26, 2026 | $251.02 | $254.11 | $249.61 | $252.26 | +0.63% | 958,847 |
| Oct 23, 2026 | $251.68 | $252.44 | $246.15 | $250.69 | -1.24% | 1,157,376 |
| Oct 22, 2026 | $240.61 | $254.41 | $240.02 | $253.84 | +5.34% | 2,237,991 |
| Oct 21, 2026 | $242.02 | $243.32 | $240.13 | $240.98 | -0.87% | 812,898 |
| Oct 20, 2026 | $236.79 | $244.65 | $235.96 | $243.10 | +4.12% | 1,492,300 |
| Oct 19, 2026 | $231.81 | $236.00 | $231.04 | $233.48 | +0.36% | 949,716 |
| Oct 16, 2026 | $235.75 | $236.87 | $232.36 | $232.65 | -1.15% | 1,462,717 |
| Oct 15, 2026 | $236.46 | $240.99 | $235.22 | $235.35 | +1.08% | 1,572,453 |
| Oct 14, 2026 | $228.99 | $234.20 | $228.00 | $232.83 | +1.72% | 1,947,327 |
| Oct 13, 2026 | $230.34 | $231.04 | $226.71 | $228.90 | -0.22% | 1,049,196 |
| Oct 12, 2026 | $233.98 | $238.24 | $229.00 | $229.41 | +1.64% | 1,462,073 |
| Oct 9, 2026 | $220.62 | $227.20 | $219.23 | $225.71 | +3.33% | 815,007 |
| Oct 8, 2026 | $220.15 | $223.09 | $215.73 | $218.43 | -1.67% | 1,339,135 |
| Oct 7, 2026 | $222.93 | $228.00 | $221.40 | $222.15 | -0.33% | 1,298,200 |
| Oct 6, 2026 | $224.53 | $225.97 | $218.00 | $222.89 | -0.31% | 1,008,096 |
| Oct 5, 2026 | $219.90 | $223.85 | $218.22 | $223.59 | +1.69% | 951,320 |
| Oct 2, 2026 | $222.98 | $224.08 | $219.81 | $219.88 | -1.32% | 780,427 |
| Oct 1, 2026 | $225.50 | $228.31 | $222.50 | $222.82 | -1.35% | 1,755,492 |
| Sep 30, 2026 | $227.23 | $229.36 | $225.51 | $225.88 | -0.52% | 1,553,331 |
| Sep 29, 2026 | $227.02 | $229.41 | $224.45 | $227.07 | -0.71% | 1,161,173 |
| Sep 28, 2026 | $225.87 | $230.49 | $225.51 | $228.69 | +0.48% | 1,332,340 |
| Sep 25, 2026 | $228.27 | $228.92 | $223.76 | $227.60 | +0.55% | 958,030 |
| Sep 24, 2026 | $226.80 | $228.72 | $224.31 | $226.36 | -0.51% | 1,034,741 |
| Sep 23, 2026 | $226.94 | $229.19 | $222.36 | $227.53 | +0.96% | 1,494,492 |
| Sep 22, 2026 | $219.22 | $226.43 | $219.00 | $225.36 | +2.87% | 1,112,343 |
| Sep 21, 2026 | $216.14 | $221.92 | $214.59 | $219.07 | +1.66% | 928,562 |
| Sep 18, 2026 | $219.05 | $220.17 | $215.26 | $215.50 | -1.62% | 2,636,086 |
| Sep 17, 2026 | $217.68 | $219.41 | $215.33 | $219.05 | +1.41% | 836,707 |
| Sep 16, 2026 | $216.41 | $218.29 | $214.81 | $216.01 | -0.07% | 606,493 |
| Sep 15, 2026 | $216.71 | $216.71 | $213.54 | $216.17 | -0.55% | 756,047 |
| Sep 14, 2026 | $221.00 | $222.25 | $215.56 | $217.36 | +0.10% | 629,931 |
| Sep 11, 2026 | $216.75 | $219.76 | $214.71 | $217.15 | +0.80% | 1,075,556 |
| Sep 10, 2026 | $209.92 | $216.70 | $208.93 | $215.43 | +2.23% | 936,643 |
| Sep 9, 2026 | $210.50 | $213.48 | $209.00 | $210.73 | -0.83% | 694,669 |
| Sep 8, 2026 | $215.45 | $217.28 | $210.54 | $212.50 | -3.77% | 617,829 |
| Sep 4, 2026 | $221.15 | $223.82 | $219.82 | $220.83 | -1.64% | 465,108 |
| Sep 3, 2026 | $225.44 | $225.80 | $221.23 | $224.51 | +0.83% | 550,745 |
| Sep 2, 2026 | $218.20 | $225.59 | $216.97 | $222.67 | +3.07% | 1,268,282 |
| Sep 1, 2026 | $218.11 | $219.30 | $213.60 | $216.04 | -0.28% | 785,496 |
| Aug 31, 2026 | $216.47 | $218.89 | $213.58 | $216.65 | -0.85% | 831,004 |
| Aug 28, 2026 | $221.17 | $222.00 | $216.78 | $218.50 | -1.35% | 517,484 |
| Aug 27, 2026 | $219.39 | $222.11 | $217.53 | $221.50 | +0.19% | 497,524 |
| Aug 26, 2026 | $219.34 | $222.00 | $218.69 | $221.07 | +0.14% | 647,334 |
| Aug 25, 2026 | $218.93 | $222.85 | $218.00 | $220.77 | +1.21% | 495,435 |
| Aug 24, 2026 | $216.40 | $218.50 | $213.96 | $218.12 | +0.62% | 649,828 |
| Aug 21, 2026 | $217.76 | $219.12 | $215.00 | $216.78 | +1.13% | 722,347 |
| Aug 20, 2026 | $217.98 | $221.29 | $214.16 | $214.35 | -3.25% | 808,625 |
| Aug 19, 2026 | $215.33 | $222.15 | $215.08 | $221.56 | +4.24% | 886,914 |
| Aug 18, 2026 | $211.00 | $214.07 | $210.01 | $212.55 | +1.63% | 694,009 |
| Aug 17, 2026 | $208.36 | $210.49 | $207.62 | $209.15 | -0.32% | 617,238 |
| Aug 14, 2026 | $210.01 | $210.79 | $208.22 | $209.83 | -0.39% | 554,816 |
| Aug 13, 2026 | $212.98 | $215.61 | $208.79 | $210.65 | +0.85% | 860,094 |
| Aug 12, 2026 | $203.52 | $209.22 | $201.00 | $208.87 | +2.44% | 789,441 |
| Aug 11, 2026 | $206.63 | $207.57 | $203.53 | $203.89 | -1.56% | 936,834 |
| Aug 10, 2026 | $206.70 | $210.02 | $206.29 | $207.13 | -0.39% | 706,425 |
| Aug 7, 2026 | $207.38 | $208.31 | $204.16 | $207.94 | +0.80% | 840,566 |
| Aug 6, 2026 | $208.75 | $209.03 | $202.03 | $206.28 | -0.17% | 892,772 |
| Aug 5, 2026 | $210.60 | $212.18 | $205.80 | $206.63 | -0.87% | 873,781 |
| Aug 4, 2026 | $200.96 | $209.74 | $199.93 | $208.45 | +3.29% | 1,205,704 |
| Aug 3, 2026 | $203.34 | $203.85 | $199.58 | $201.82 | -0.56% | 940,993 |
| Jul 31, 2026 | $207.51 | $208.05 | $202.57 | $202.95 | -2.40% | 1,062,258 |
| Jul 30, 2026 | $204.38 | $210.19 | $203.09 | $207.93 | -0.62% | 892,938 |
| Jul 29, 2026 | $210.50 | $218.59 | $206.27 | $209.23 | +1.76% | 2,400,174 |
| Jul 28, 2026 | $201.01 | $207.72 | $199.40 | $205.61 | +2.73% | 1,832,179 |
| Jul 27, 2026 | $202.75 | $204.47 | $199.83 | $200.14 | -1.01% | 762,581 |
| Jul 24, 2026 | $202.24 | $203.30 | $200.04 | $202.19 | +0.78% | 596,372 |
| Jul 23, 2026 | $197.04 | $203.60 | $196.92 | $200.62 | +1.46% | 1,032,070 |
| Jul 22, 2026 | $203.70 | $204.31 | $197.40 | $197.74 | -2.67% | 841,350 |
| Jul 21, 2026 | $199.47 | $203.70 | $198.59 | $203.16 | +1.61% | 652,841 |
| Jul 20, 2026 | $204.08 | $205.65 | $199.62 | $199.95 | -2.93% | 963,088 |
| Jul 17, 2026 | $208.60 | $215.79 | $203.40 | $205.99 | -1.40% | 1,151,283 |
| Jul 16, 2026 | $198.26 | $209.64 | $194.67 | $208.92 | +5.92% | 1,872,778 |
| Jul 15, 2026 | $191.21 | $198.58 | $186.03 | $197.24 | +2.76% | 2,067,350 |
| Jul 14, 2026 | $200.34 | $202.00 | $189.40 | $191.95 | -8.17% | 3,902,309 |
| Jul 13, 2026 | $199.33 | $210.87 | $197.74 | $209.03 | +4.96% | 2,259,821 |
| Jul 10, 2026 | $197.63 | $199.98 | $194.37 | $199.15 | +0.12% | 1,133,120 |
| Jul 9, 2026 | $198.92 | $201.01 | $196.00 | $198.91 | -0.72% | 1,657,327 |
| Jul 8, 2026 | $204.86 | $206.75 | $198.93 | $200.36 | -2.60% | 1,947,888 |
| Jul 7, 2026 | $211.86 | $212.00 | $205.65 | $205.70 | -1.32% | 1,156,880 |
| Jul 6, 2026 | $215.95 | $215.95 | $208.27 | $208.46 | -3.54% | 1,218,492 |
| Jul 2, 2026 | $212.74 | $219.02 | $210.75 | $216.12 | +3.04% | 1,155,165 |
| Jul 1, 2026 | $215.25 | $215.81 | $209.67 | $209.74 | -2.93% | 1,138,639 |
| Jun 30, 2026 | $218.00 | $218.00 | $212.58 | $216.06 | -0.26% | 1,091,325 |
| Jun 29, 2026 | $215.74 | $219.72 | $214.08 | $216.63 | +0.28% | 1,279,990 |
| Jun 26, 2026 | $202.53 | $218.06 | $202.29 | $216.03 | +6.97% | 2,374,525 |
| Jun 25, 2026 | $201.63 | $206.67 | $200.20 | $201.96 | +1.19% | 1,328,911 |
| Jun 24, 2026 | $199.34 | $202.06 | $198.66 | $199.59 | +1.22% | 1,349,120 |
| Jun 23, 2026 | $198.88 | $201.22 | $197.01 | $197.19 | -1.26% | 1,053,492 |
| Jun 22, 2026 | $199.48 | $200.98 | $194.74 | $199.71 | +1.59% | 1,675,111 |
| Jun 18, 2026 | $200.22 | $200.99 | $193.20 | $196.58 | -1.05% | 1,729,826 |
| Jun 17, 2026 | $195.14 | $201.75 | $194.04 | $198.67 | +1.56% | 1,009,032 |
| Jun 16, 2026 | $199.69 | $200.26 | $194.04 | $195.61 | -1.53% | 1,110,656 |
| Jun 15, 2026 | $198.37 | $199.37 | $195.89 | $198.64 | -0.70% | 883,963 |
| Jun 12, 2026 | $200.57 | $203.45 | $199.06 | $200.05 | +0.05% | 837,294 |
| Jun 11, 2026 | $195.49 | $201.18 | $194.24 | $199.96 | +2.94% | 914,781 |
| Jun 10, 2026 | $200.21 | $201.94 | $194.10 | $194.24 | -2.44% | 1,071,228 |
| Jun 9, 2026 | $195.51 | $199.63 | $193.45 | $199.10 | +3.36% | 934,191 |
| Jun 8, 2026 | $197.25 | $198.70 | $192.18 | $192.62 | -1.39% | 1,162,350 |
| Jun 5, 2026 | $196.45 | $200.66 | $195.14 | $195.34 | -0.57% | 880,438 |
| Jun 4, 2026 | $198.00 | $199.90 | $196.35 | $196.45 | +0.25% | 719,127 |
| Jun 3, 2026 | $187.69 | $196.51 | $187.48 | $195.96 | +3.78% | 891,787 |
| Jun 2, 2026 | $190.09 | $190.58 | $184.90 | $188.83 | -1.77% | 1,098,098 |
| Jun 1, 2026 | $194.50 | $195.28 | $191.67 | $192.23 | -1.92% | 841,499 |
| May 29, 2026 | $195.55 | $198.46 | $195.11 | $196.00 | -0.20% | 1,905,488 |
| May 28, 2026 | $196.97 | $198.00 | $194.50 | $196.39 | -0.29% | 556,331 |
| May 27, 2026 | $194.11 | $199.80 | $194.11 | $196.97 | +2.01% | 893,048 |
| May 26, 2026 | $194.30 | $195.50 | $192.27 | $193.08 | -0.35% | 930,212 |
| May 22, 2026 | $190.53 | $194.75 | $190.01 | $193.76 | +2.26% | 892,933 |
| May 21, 2026 | $187.40 | $190.27 | $185.85 | $189.47 | +0.89% | 1,475,348 |
| May 20, 2026 | $191.41 | $193.38 | $186.37 | $187.80 | -1.45% | 919,894 |
| May 19, 2026 | $191.72 | $193.03 | $188.64 | $190.56 | -0.70% | 1,054,138 |
| May 18, 2026 | $191.25 | $193.37 | $189.19 | $191.91 | -0.54% | 1,051,356 |
| May 15, 2026 | $191.83 | $194.91 | $190.66 | $192.95 | +0.83% | 1,252,270 |
| May 14, 2026 | $200.25 | $205.00 | $189.49 | $191.37 | -6.43% | 2,812,933 |
| May 13, 2026 | $199.33 | $205.97 | $198.86 | $204.53 | +2.59% | 1,272,026 |
| May 12, 2026 | $198.47 | $202.40 | $196.47 | $199.36 | +0.71% | 1,145,749 |
| May 11, 2026 | $194.76 | $200.31 | $194.75 | $197.95 | +2.33% | 1,772,229 |
| May 8, 2026 | $189.68 | $195.20 | $189.50 | $193.45 | +1.08% | 931,578 |
| May 7, 2026 | $190.34 | $192.10 | $188.86 | $191.38 | +0.37% | 735,692 |
| May 6, 2026 | $189.13 | $191.17 | $188.30 | $190.68 | +0.82% | 741,346 |
| May 5, 2026 | $187.38 | $189.69 | $186.00 | $189.13 | +1.03% | 586,074 |
| May 4, 2026 | $186.28 | $187.51 | $185.44 | $187.21 | +0.08% | 626,559 |
| May 1, 2026 | $189.28 | $190.57 | $186.14 | $187.06 | -1.17% | 696,812 |
| Apr 30, 2026 | $194.02 | $195.98 | $187.16 | $189.28 | -2.62% | 1,550,523 |
| Apr 29, 2026 | $183.12 | $195.89 | $180.18 | $194.38 | +6.00% | 2,453,836 |
| Apr 28, 2026 | $182.45 | $184.41 | $181.89 | $183.38 | +1.50% | 1,235,813 |
| Apr 27, 2026 | $183.16 | $186.15 | $179.15 | $180.67 | -2.01% | 1,101,370 |
| Apr 24, 2026 | $186.65 | $186.65 | $183.17 | $184.38 | -1.86% | 723,366 |
| Apr 23, 2026 | $189.46 | $190.32 | $187.01 | $187.88 | -1.15% | 816,281 |
| Apr 22, 2026 | $189.31 | $192.75 | $188.67 | $190.07 | +2.22% | 1,328,297 |
| Apr 21, 2026 | $184.52 | $187.74 | $181.75 | $185.95 | +1.42% | 1,063,303 |
| Apr 20, 2026 | $179.54 | $184.26 | $178.72 | $183.34 | +3.38% | 1,484,371 |
| Apr 17, 2026 | $176.29 | $178.41 | $175.69 | $177.35 | +0.76% | 1,239,458 |
| Apr 16, 2026 | $178.82 | $179.99 | $174.85 | $176.02 | -2.50% | 953,722 |
| Apr 15, 2026 | $179.36 | $180.87 | $177.70 | $180.54 | +0.88% | 1,168,801 |
| Apr 14, 2026 | $177.71 | $181.77 | $177.45 | $178.96 | +1.47% | 1,550,580 |
| Apr 13, 2026 | $172.62 | $176.79 | $171.22 | $176.37 | +1.96% | 1,414,958 |
| Apr 10, 2026 | $177.97 | $177.97 | $172.32 | $172.97 | -2.34% | 1,501,979 |
| Apr 9, 2026 | $177.81 | $180.06 | $174.97 | $177.11 | -1.55% | 1,266,491 |
| Apr 8, 2026 | $178.24 | $180.24 | $176.35 | $179.90 | +2.44% | 1,289,686 |
| Apr 7, 2026 | $172.20 | $175.64 | $170.43 | $175.61 | +1.90% | 1,515,806 |
| Apr 6, 2026 | $177.00 | $177.39 | $168.64 | $172.34 | -2.82% | 2,149,104 |
| Apr 2, 2026 | $181.46 | $182.23 | $176.39 | $177.34 | -3.50% | 1,339,297 |
| Apr 1, 2026 | $183.16 | $186.31 | $181.71 | $183.78 | +0.25% | 1,390,216 |
| Mar 31, 2026 | $179.46 | $184.68 | $171.37 | $183.33 | -2.26% | 2,719,977 |
| Mar 30, 2026 | $186.16 | $190.09 | $185.51 | $187.57 | +2.03% | 799,935 |
| Mar 27, 2026 | $191.06 | $191.06 | $183.01 | $183.84 | -3.78% | 935,104 |
| Mar 26, 2026 | $189.00 | $192.28 | $188.36 | $191.06 | +0.99% | 879,198 |
| Mar 25, 2026 | $184.91 | $189.38 | $184.91 | $189.18 | +2.85% | 775,195 |
| Mar 24, 2026 | $182.63 | $184.84 | $180.33 | $183.94 | +0.16% | 644,275 |
| Mar 23, 2026 | $183.48 | $185.00 | $183.00 | $183.64 | +1.20% | 1,011,752 |
| Mar 20, 2026 | $183.13 | $183.69 | $180.47 | $181.46 | -1.06% | 2,214,268 |
| Mar 19, 2026 | $182.18 | $185.45 | $181.68 | $183.41 | +0.60% | 768,649 |
| Mar 18, 2026 | $184.13 | $184.32 | $180.48 | $182.31 | -1.61% | 846,255 |
| Mar 17, 2026 | $184.73 | $186.52 | $183.20 | $185.29 | +1.11% | 810,219 |
| Mar 16, 2026 | $182.75 | $184.62 | $181.88 | $183.26 | +0.94% | 995,911 |
| Mar 13, 2026 | $185.99 | $188.00 | $181.46 | $181.55 | -1.81% | 1,092,301 |
| Mar 12, 2026 | $187.86 | $188.91 | $184.63 | $184.90 | -2.93% | 851,563 |
| Mar 11, 2026 | $187.54 | $192.99 | $187.54 | $190.48 | +1.10% | 864,392 |
| Mar 10, 2026 | $187.69 | $190.78 | $187.02 | $188.41 | +0.09% | 687,662 |
| Mar 9, 2026 | $183.91 | $188.50 | $182.60 | $188.24 | +1.82% | 651,626 |
| Mar 6, 2026 | $186.25 | $186.25 | $181.24 | $184.87 | -1.71% | 772,906 |
| Mar 5, 2026 | $187.97 | $190.99 | $185.95 | $188.08 | -0.98% | 893,331 |
| Mar 4, 2026 | $185.06 | $190.37 | $183.16 | $189.94 | +3.22% | 952,927 |
| Mar 3, 2026 | $185.01 | $187.05 | $181.79 | $184.02 | -2.14% | 1,049,925 |
| Mar 2, 2026 | $190.22 | $190.75 | $186.72 | $188.05 | -1.97% | 691,597 |
| Feb 27, 2026 | $187.51 | $192.46 | $186.62 | $191.82 | +2.02% | 1,402,201 |
| Feb 26, 2026 | $190.30 | $190.74 | $185.90 | $188.02 | -1.42% | 988,117 |
| Feb 25, 2026 | $194.23 | $196.73 | $189.89 | $190.73 | -2.25% | 942,723 |
| Feb 24, 2026 | $196.03 | $198.72 | $194.43 | $195.13 | -0.62% | 716,382 |
| Feb 23, 2026 | $191.82 | $197.05 | $189.11 | $196.34 | +2.24% | 878,939 |
| Feb 20, 2026 | $190.78 | $192.60 | $189.95 | $192.03 | -0.03% | 799,225 |
| Feb 19, 2026 | $193.51 | $195.00 | $191.05 | $192.08 | -1.06% | 993,273 |
| Feb 18, 2026 | $195.32 | $195.68 | $193.11 | $194.13 | -0.76% | 1,049,036 |
| Feb 17, 2026 | $197.46 | $200.29 | $193.37 | $195.62 | -0.46% | 986,535 |
| Feb 13, 2026 | $196.27 | $199.50 | $195.52 | $196.52 | +0.52% | 1,352,792 |
| Feb 12, 2026 | $190.15 | $196.00 | $189.00 | $195.50 | +2.25% | 1,657,480 |
| Feb 11, 2026 | $188.35 | $192.00 | $187.20 | $191.20 | +1.17% | 996,929 |
| Feb 10, 2026 | $194.07 | $195.72 | $188.74 | $188.99 | -2.49% | 1,836,221 |
| Feb 9, 2026 | $199.83 | $201.00 | $191.88 | $193.81 | -3.66% | 2,096,252 |
| Feb 6, 2026 | $187.01 | $202.41 | $184.60 | $201.18 | +8.53% | 3,404,876 |
| Feb 5, 2026 | $184.87 | $187.73 | $184.54 | $185.36 | -0.05% | 2,542,641 |
| Feb 4, 2026 | $177.25 | $186.24 | $177.10 | $185.45 | +4.92% | 2,076,363 |
| Feb 3, 2026 | $177.79 | $182.67 | $176.19 | $176.76 | -1.30% | 1,594,142 |
| Feb 2, 2026 | $179.30 | $180.76 | $177.58 | $179.09 | -0.44% | 1,288,816 |
| Jan 30, 2026 | $177.09 | $180.14 | $175.96 | $179.89 | +2.11% | 1,487,978 |
| Jan 29, 2026 | $174.88 | $177.20 | $173.51 | $176.18 | +0.77% | 1,146,709 |
| Jan 28, 2026 | $173.63 | $175.06 | $170.85 | $174.83 | +0.41% | 1,304,662 |
| Jan 27, 2026 | $173.02 | $176.14 | $172.23 | $174.12 | +0.58% | 748,078 |
| Jan 26, 2026 | $171.67 | $174.31 | $170.59 | $173.12 | +0.89% | 1,049,188 |
| Jan 23, 2026 | $173.17 | $173.90 | $170.04 | $171.59 | -1.27% | 1,250,463 |
| Jan 22, 2026 | $171.78 | $175.29 | $171.65 | $173.80 | +0.68% | 996,425 |
| Jan 21, 2026 | $165.31 | $172.87 | $165.31 | $172.62 | +4.38% | 1,447,089 |
| Jan 20, 2026 | $161.51 | $165.61 | $160.36 | $165.38 | +0.58% | 1,879,947 |
| Jan 16, 2026 | $168.87 | $169.34 | $163.74 | $164.42 | -2.46% | 1,816,538 |
| Jan 15, 2026 | $169.03 | $169.79 | $166.79 | $168.57 | -0.44% | 1,562,727 |
| Jan 14, 2026 | $177.73 | $178.41 | $165.58 | $169.31 | -5.04% | 3,635,883 |
| Jan 13, 2026 | $185.42 | $186.32 | $177.05 | $178.30 | -3.95% | 1,597,380 |
| Jan 12, 2026 | $188.00 | $188.00 | $182.73 | $185.63 | -1.06% | 1,280,360 |
| Jan 9, 2026 | $186.74 | $190.20 | $186.49 | $187.62 | +0.87% | 1,416,702 |
| Jan 8, 2026 | $187.02 | $187.77 | $183.50 | $186.00 | -0.49% | 1,622,749 |
| Jan 7, 2026 | $181.70 | $187.06 | $181.70 | $186.91 | +2.35% | 2,122,447 |
| Jan 6, 2026 | $174.94 | $182.97 | $174.30 | $182.61 | +4.57% | 2,115,650 |
| Jan 5, 2026 | $175.73 | $180.56 | $171.61 | $174.63 | -1.79% | 1,663,631 |
| Jan 2, 2026 | $175.37 | $178.24 | $174.28 | $177.82 | +1.04% | 1,095,744 |
| Dec 31, 2025 | $175.76 | $177.19 | $175.02 | $175.99 | -0.23% | 890,441 |
| Dec 30, 2025 | $176.30 | $176.99 | $175.72 | $176.40 | -0.24% | 609,867 |
| Dec 29, 2025 | $177.00 | $178.46 | $176.31 | $176.83 | -0.14% | 928,193 |
| Dec 26, 2025 | $175.30 | $177.19 | $175.00 | $177.08 | +0.43% | 687,403 |
| Dec 24, 2025 | $175.73 | $177.18 | $175.37 | $176.33 | +0.86% | 434,748 |
| Dec 23, 2025 | $174.26 | $175.58 | $173.08 | $174.82 | +0.07% | 1,281,705 |
| Dec 22, 2025 | $174.78 | $177.29 | $172.90 | $174.70 | -0.06% | 1,909,529 |
| Dec 19, 2025 | $171.32 | $176.42 | $170.00 | $174.80 | +2.88% | 14,994,760 |
| Dec 18, 2025 | $171.59 | $173.00 | $168.56 | $169.91 | -1.27% | 2,761,018 |
| Dec 17, 2025 | $171.43 | $173.83 | $169.55 | $172.10 | +0.35% | 2,783,560 |
| Dec 16, 2025 | $174.51 | $174.51 | $169.52 | $171.50 | -2.41% | 2,408,490 |
| Dec 15, 2025 | $173.67 | $175.94 | $170.45 | $175.74 | +0.94% | 2,291,589 |
| Dec 12, 2025 | $173.49 | $175.08 | $171.27 | $174.10 | +0.93% | 1,781,471 |
| Dec 11, 2025 | $177.47 | $180.79 | $172.00 | $172.50 | -2.84% | 2,721,790 |
| Dec 10, 2025 | $173.30 | $178.17 | $169.24 | $177.55 | +0.97% | 2,147,901 |
| Dec 9, 2025 | $179.91 | $181.99 | $175.39 | $175.84 | -2.55% | 1,506,685 |
| Dec 8, 2025 | $181.30 | $182.12 | $179.21 | $180.44 | -0.47% | 1,474,568 |
| Dec 5, 2025 | $181.96 | $183.15 | $181.10 | $181.30 | -0.37% | 1,209,961 |
| Dec 4, 2025 | $181.86 | $182.69 | $179.27 | $181.98 | +0.68% | 1,246,342 |
| Dec 3, 2025 | $180.17 | $182.94 | $178.05 | $180.75 | +0.32% | 1,845,129 |
| Dec 2, 2025 | $177.32 | $180.55 | $174.53 | $180.18 | +1.35% | 1,866,647 |
| Dec 1, 2025 | $180.15 | $181.78 | $175.88 | $177.78 | -2.37% | 1,947,020 |
| Nov 28, 2025 | $182.07 | $182.74 | $180.69 | $182.09 | +0.08% | 566,362 |
| Nov 26, 2025 | $181.96 | $183.93 | $180.76 | $181.94 | -0.01% | 1,483,073 |
| Nov 25, 2025 | $177.07 | $182.97 | $176.09 | $181.96 | +2.91% | 2,344,782 |
| Nov 24, 2025 | $177.65 | $185.17 | $175.57 | $176.82 | +0.87% | 4,164,240 |
| Nov 21, 2025 | $168.54 | $176.02 | $167.42 | $175.30 | +4.23% | 2,268,169 |
| Nov 20, 2025 | $168.15 | $170.91 | $165.75 | $168.18 | +0.15% | 1,914,503 |
| Nov 19, 2025 | $168.83 | $168.90 | $165.79 | $167.93 | -0.53% | 1,765,993 |
| Nov 18, 2025 | $164.40 | $170.78 | $163.00 | $168.83 | +2.52% | 2,257,470 |
| Nov 17, 2025 | $167.00 | $167.97 | $163.50 | $164.68 | -1.71% | 2,245,006 |
| Nov 14, 2025 | $164.72 | $169.00 | $163.00 | $167.55 | +1.71% | 2,620,813 |
| Nov 13, 2025 | $161.57 | $167.87 | $161.20 | $164.73 | +2.01% | 2,993,001 |
| Nov 12, 2025 | $160.00 | $162.56 | $158.05 | $161.48 | +1.20% | 1,659,866 |
| Nov 11, 2025 | $156.76 | $159.95 | $154.20 | $159.56 | +2.11% | 1,504,613 |
| Nov 10, 2025 | $155.41 | $156.55 | $153.77 | $156.26 | +0.48% | 1,258,595 |
| Nov 7, 2025 | $156.70 | $156.70 | $151.83 | $155.51 | -0.78% | 1,552,011 |
| Nov 6, 2025 | $155.76 | $157.80 | $153.76 | $156.74 | +2.16% | 1,848,716 |
| Nov 5, 2025 | $149.66 | $153.68 | $148.51 | $153.43 | +2.75% | 1,806,070 |
| Nov 4, 2025 | $150.89 | $152.90 | $149.05 | $149.33 | -1.39% | 2,029,011 |
| Nov 3, 2025 | $153.60 | $155.33 | $149.63 | $151.44 | -1.83% | 2,197,357 |
| Oct 31, 2025 | $147.99 | $155.18 | $146.52 | $154.27 | +3.11% | 2,235,290 |
| Oct 30, 2025 | $140.10 | $154.44 | $138.00 | $149.61 | +1.18% | 2,745,188 |
| Oct 29, 2025 | $148.82 | $149.91 | $147.54 | $147.86 | -0.85% | 2,450,701 |
| Oct 28, 2025 | $150.01 | $150.30 | $148.37 | $149.13 | -0.86% | 1,662,855 |
| Oct 27, 2025 | $150.07 | $150.92 | $148.10 | $150.43 | +0.36% | 1,214,395 |
| Oct 24, 2025 | $151.09 | $151.92 | $148.98 | $149.89 | -0.13% | 1,338,315 |
| Oct 23, 2025 | $148.99 | $150.29 | $147.57 | $150.08 | +1.60% | 1,245,964 |
| Oct 22, 2025 | $147.37 | $149.12 | $146.25 | $147.72 | +1.03% | 1,403,299 |
| Oct 21, 2025 | $146.09 | $147.89 | $144.29 | $146.22 | -0.28% | 895,048 |
| Oct 20, 2025 | $143.31 | $147.47 | $142.41 | $146.63 | – | 1,316,452 |
Seasonality
BIIB return in each calendar month over the last 10 years, including dividends. The current month runs to the latest close.
| Year | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Average | 1.5% | -2.5% | -3.8% | -1.5% | 0.7% | 4.0% | 0.9% | 1.2% | 2.5% | 0.8% | 1.5% | -1.7% |
| Months up | 5 of 10 | 3 of 10 | 3 of 10 | 2 of 10 | 6 of 10 | 6 of 10 | 6 of 10 | 6 of 10 | 4 of 10 | 4 of 10 | 5 of 9 | 3 of 9 |
| 2026 | 2.2% | 6.6% | -4.4% | 3.2% | 3.6% | 10.2% | -6.1% | 6.8% | 4.3% | 12.3% | ||
| 2025 | -5.9% | -2.4% | -2.6% | -11.5% | 7.2% | -3.2% | 1.9% | 3.3% | 5.9% | 10.1% | 18.0% | -3.3% |
| 2024 | -4.7% | -12.0% | -0.6% | -0.4% | 4.7% | 3.1% | -8.0% | -4.0% | -5.3% | -10.2% | -7.7% | -4.8% |
| 2023 | 5.0% | -7.2% | 3.0% | 9.4% | -2.6% | -3.9% | -5.1% | -1.0% | -3.9% | -7.6% | -1.5% | 10.5% |
| 2022 | -5.8% | -6.6% | -0.2% | -1.5% | -3.6% | 2.0% | 5.5% | -9.2% | 36.7% | 6.2% | 7.7% | -9.3% |
| 2021 | 15.4% | -3.4% | 2.5% | -4.4% | 0.1% | 29.5% | -5.6% | 3.7% | -16.5% | -5.8% | -11.6% | 1.8% |
| 2020 | -9.4% | 14.7% | 2.6% | -6.2% | 3.5% | -12.9% | 2.7% | 4.7% | -1.4% | -11.1% | -4.7% | 2.0% |
| 2019 | 10.9% | -1.7% | -27.9% | -3.0% | -4.3% | 6.6% | 1.7% | -7.6% | 5.9% | 28.3% | 0.4% | -1.0% |
| 2018 | 9.2% | -16.9% | -5.2% | -0.1% | 7.4% | -1.3% | 15.2% | 5.7% | -0.1% | -13.9% | 9.7% | -9.8% |
| 2017 | -2.2% | 4.1% | -5.3% | -0.8% | -8.6% | 9.5% | 6.7% | 9.3% | -1.1% | -0.5% | 3.4% | -1.1% |