Biogen’s 10.09% Surge Drives $610M Volume, Ranks 209th in U.S. Equity Trading Amid Alzheimer’s Breakthrough and Expansion Plans

Biogen (NASDAQ: BIIB) surged 10.09% on October 1, 2025, with a trading volume of $610 million, marking a 219.23% increase from the previous day. The stock ranked 209th in volume among U.S. equities, reflecting heightened investor activity amid key developments.

Recent updates highlighted Biogen’s progress in Alzheimer’s drug development, including positive Phase III trial results for its experimental therapy Lecanemab. Analysts noted that the data reinforced confidence in the treatment’s potential to capture a significant share of the $100 billion dementia market. Additionally, the company announced a partnership with a major European biotech firm to co-develop gene therapies, broadening its pipeline and reducing R&D costs through shared resources.

Investor sentiment was further supported by Biogen’s updated guidance for 2025, which projected a 12% revenue increase from its multiple sclerosis portfolio due to strong demand in emerging markets. The company also confirmed plans to expand manufacturing capacity by 2026, addressing supply constraints that had previously limited growth.

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