Shares of Eli Lilly (LLY 0.78%) jumped 39.2% in 2025, according to data from S&P Global Market Intelligence. The drugmaker is seeing soaring sales due to its blockbuster weight loss products called Zepbound and Mounjaro, as well as a pipeline of other drugs. It has just surpassed a market cap of $1 trillion, making it the 12th largest company in the world.
Here's why Eli Lilly stock was soaring in 2025, and whether it is a buy right now at a trillion-dollar market cap.
NYSE: LLY
Key Data Points
Huge potential in weight-loss drugs
The weight-loss drug revolution is here. By countering cravings metabolically, these drugs have helped curb the troubling trend of obesity in the United States, a pandemic that has been raging for decades. Obesity rates have peaked in the country since 2022 and have fallen ever since.
With a rapid deployment of these drugs to patients as supply is unlocked by makers like Eli Lilly, this rate of obesity should keep falling. Last quarter, Eli Lilly's revenue grew 54% year-over-year to $17.6 billion, an impressive level of growth for a megacap company.
The business also has a pipeline of other drugs, such as Kisunla, which is for early stage Alzheimer's disease. Looking at Mounjaro and Zepbound specifically, both of these drugs are experiencing sales growth of over 100% year-over-year at the moment and have plenty of room to expand their sales pipelines globally.
Momentum in weight-loss drugs is the main reason why Eli Lilly's stock soared in 2025. Over the last five years it is up 459%, and that is excluding dividends. It is the largest drugmaker in the world and is firing on all cylinders at the moment.
Image source: Getty Images.
Time to buy Eli Lilly stock?
After this massive stock price appreciation, Eli Lilly now has a price-to-earnings ratio (P/E) of 53, which is well above the S&P 500 average. Investors are betting that the momentum in weight-loss drugs will continue as these drugs help fight obesity around the globe. There is still much progress to be made, with the rate of obesity only falling from 40% in 2022 to 37% today. If Eli Lilly is successful, that number could be much lower 10 years from now.
With this growth potential in mind, Eli Lilly looks like a reasonably priced stock, even with its premium current P/E ratio.
