Biotech investors grow uneasy as XBI stalls despite overall gains

Adam Feuerstein notes that while biotech stocks have performed well overall this year, investor sentiment has turned sour after the summer.

The SPDR S&P Biotech ETF (XBI) remains up about 24% year‑to‑date, but it has slipped roughly 11% from its August peak, a decline that is modest compared with the deep downturn seen in early 2025.

Feuerstein argues that the real source of anxiety is not the headline numbers but underlying issues that are not visible in the index’s performance, suggesting a brewing challenge for the sector.