Why Regeneron (REGN) Shares Are Falling Today

What Happened?

Shares of biotech company Regeneron (NASDAQ:REGN) fell 19% in the afternoon session after the company announced mixed results from its Phase 3 trials for itepekimab, an experimental drug for Chronic Obstructive Pulmonary Disease (COPD). 

While one trial met its primary endpoint, the other missed, raising concerns about the drug's future and delaying its potential market entry. This setback, likely spooked investors and contributed to the significant decline.

The stock market overreacts to news, and big price drops can present good opportunities to buy high-quality stocks. Is now the time to buy Regeneron? Access our full analysis report here, it’s free.

What The Market Is Telling Us

Regeneron’s shares are not very volatile and have only had 9 moves greater than 5% over the last year. Moves this big are rare for Regeneron and indicate this news significantly impacted the market’s perception of the business.

The biggest move we wrote about over the last year was about 1 month ago when the stock dropped 9.6% on the news that the company reported weak first-quarter 2025 results. Its revenue missed significantly, and its EPS fell short of Wall Street's estimates. Revenue declined 4% from the prior year, as Regeneron struggled to offset the double-digit decline in net product sales. Overall, this quarter could have been better.

Regeneron is down 31.8% since the beginning of the year, and at $487.82 per share, it is trading 59.4% below its 52-week high of $1,202 from August 2024. Investors who bought $1,000 worth of Regeneron’s shares 5 years ago would now be looking at an investment worth $813.74.

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