(Bloomberg) -- Investors who may have missed out on the blistering rally in Eli Lilly & Co. and Novo Nordisk A/S are once again taking a chance with Amgen Inc.

The shares surged 12% Friday, the biggest one-day jump for Amgen in nearly 15 years, fueled by fresh optimism about the company’s future in the lucrative market for weight-loss drugs after upbeat commentary from the chief executive officer.

Although it could take years for a drug to come to market, investors who are looking for new ways trade into the hype are betting that the Amgen’s anti-obesity entrant, MariTide, could compete against current blockbusters. Wall Street’s enthusiasm for medicines tied to weight loss has supercharged Lilly, which is now the biggest health-care company in the world by market value. Likewise, Novo is the most valuable listed company in Europe and other runners up have also notched healthy gains.

Read more: Here Are the Obesity Drug Hopefuls Vying to Unseat Lilly, Novo

“There’s a clear enthusiasm to get more things on market and try to have something that is differentiated so that even if you are three or four years behind getting to market, you can gain meaningful market share,” said William Blair analyst Matt Phipps, who upgraded his rating on the stock to outperform after the CEO’s comments.

It’s not the first time that investors have ridden the weight-loss wave when it comes to Amgen. Market exuberance in late 2022 sent the stock skyrocketing after early data on the drug’s potential, but the sentiment soon faded. Investors roused again at the beginning of 2024 ahead of another batch of data. But the results raised safety concerns, dampening optimism, and the stock’s climb. 

The Thousand Oaks, California-based company’s shares have climbed about 27% in the past three years while Lilly and Novo have both more than trebled. Amgen’s valuation premium sits at a five-year average of about 15 times forward earnings, below Novo’s and well short of Lilly’s 51. 

“These pile-ins tend to be short lived,” said Mizuho analyst Salim Syed, who remains neutral on Amgen. “Now is the third time we’re seeing this, and every single time, the stock tends to cool off afterward.”

With detailed data from a mid-stage study not expected until the end of the year, Syed doesn’t see anything that could take the stock even higher.

“The onus is going to be on Amgen to prove that they have a compound that people are willing to ascribe this much value to,” Syed added. “If that data does not pan out, the stock is likely going to go substantially lower.”

Most on Wall Street are more enthusiastic — more than half of the analysts tracked by Bloomberg recommend buying the stock. William Blair’s Phipps sees MariTide as having “multi-blockbuster” potential despite Lilly and Novo’s current dominance, and a cadre of would-be competitors racing to develop newer treatments.

“There is that kind of ability to see real meaningful upside from one product like this and that can give you significant longer term growth and revenue and earnings upside,” Phipps said. 

--With assistance from Madison Muller.

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