West Pharmaceutical Services (WST) saw its shares plummet 7.52% during intraday trading on Thursday, a sharp reversal from earlier gains. The company had initially traded higher after reporting fourth-quarter results that exceeded analyst expectations and issuing 2026 profit guidance above estimates.

The downturn appears linked to cautious commentary from company executives during a conference call. Management indicated that while demand for GLP-1 related drugs is expected to grow in 2026, the pace is anticipated to be slower than in 2025. Furthermore, executives noted that GLP-1 adoption rates would need to exceed 30% to deliver 10% year-over-year growth for the company, a level described as "more aggressive" than current expectations.

Investor concerns about the potential impact of oral weight-loss drugs on the injectables market, for which West Pharmaceutical supplies key components, also contributed to the selling pressure. The shift in sentiment during the trading session highlights market sensitivity to growth projections despite strong quarterly performance.