The thesis

Eli Lilly commercializes the leading approved GLP-1 drugs in Mounjaro and Zepbound, and obesity and diabetes now drive its revenue mix. Revenue grew 38.6% year over year behind an 83.6% gross margin and a 31.9% net margin, so the growth is highly profitable. Analysts consensus rates the stock a buy, yet our conviction score sits at just 29 out of 100, a watchlist signal that the setup is richly valued relative to its evidence base. The tension is the story: exceptional fundamentals already carry a 43.9x price-to-earnings multiple, leaving the bull case dependent on continued flawless execution.

Why now

US Zepbound revenue grew 122% year over year in Q4 2025 per Lilly investor relations, confirming demand acceleration rather than deceleration. A post-election risk-on rotation toward growth names adds a macro tailwind that could re-rate already expensive shares further.

What to watch

Quarterly US Zepbound and Mounjaro revenue growth rates versus the 122% and 38.6% benchmarks; a deceleration below revenue growth in the high thirties breaks the thesis. Watch competitor GLP-1 pipeline readouts and any shift in the risk-on rotation signal over the next one to three quarters.

Key risks

At 43.9x earnings, any slowdown in tirzepatide growth or pricing pressure would compress the multiple sharply. Competitive pipeline risk in GLP-1 means rival oral and next-generation obesity drugs could erode Lilly's share before the valuation pays off. A rotation back out of risk-on growth names would hit the stock regardless of company-specific news.

Theme exposure