GFI vs BIIB Comparison

Gold Fields Ltd is a producer of gold and is a holder of gold reserves and resources in South Africa, Ghana, Australia, and Peru. In Peru, the company also produces copper. The company is involved in underground and surface gold and surface copper mining and silver and related activities, including exploration, extraction, processing, and smelting. It conducts underground and surface mining operations at St. Ives, underground-only operations at Agnew, Granny Smith, and South Deep, and surface-only open pit mining at Damang, Tarkwa, and Cerro Corona. The company's revenues are derived from the sale of gold that it produces.

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).