Europe’s Top Stock Index to Get a €38 Billion Biotech Giant (1)

The euro area’s top stock benchmark is welcoming a rare entry by a biotech firm, promising to ignite fresh interest in a sector that’s been long ignored by the region’s cautious investors.

Argenx SE, valued at €38 billion ($45 billion) after a roughly 7,200% rally since listing in Brussels more than 11 years ago, will make its entry to the Euro Stoxx 50 index on Monday. It will be the first biotech to be added to the gauge since at least 2002, when Bloomberg began tracking the index’s changes.

Analysts say the stock still has ample upside, driven by ...