ACGL vs BIIB Comparison

Arch Capital Group Ltd is a Bermuda company that writes insurance and reinsurance with operations in the United States, Canada, Europe, Australia, and the United Kingdom. The business operates through three underwriting segments: insurance, reinsurance, and mortgage. The insurance segment provides specialty risk solutions to clients across various industries. The reinsurance segment provides reinsurance services which cover property catastrophe, property, liability, marine, aviation and space, trade credit and surety, agriculture, accident, life and health, and political risk. The mortgage business provides risk management and risk financing products to the mortgage insurance sectors through platforms in the U.S., Europe and Bermuda.

Biogen is an established biopharmaceutical company focused on treatments for neurodegenerative and rare diseases. Its declining multiple sclerosis franchise is its largest revenue generator and contributed 40% of total revenue in 2025. Biogen also generates significant revenue from its CD20 collaboration agreements with Roche (19% of total in 2025), which includes oncology drugs Rituxan and Gazyva and multiple sclerosis drug Ocrevus. Biogen's newer franchises include Spinraza (spinal muscular atrophy, with partner Ionis), Leqembi (Alzheimer's disease, collabroation revenue from its partner Eisai), Skyclarys (Friedreich's ataxia, Reata), Zurzuvae (postpartum depression, Sage), and Qalsody (amyotrophic lateral sclerosis, Ionis).