The pharma giant’s stock was up more than 6% as of 10:15 a.m. ET, hitting an all-time high as the Dow tumbled over 600 points. The gain comes as fears rise about a rebound of COVID-19 throughout America. (Shares of other approved vaccine manufacturers Pfizer and Johnson & Johnson were both largely flat.)

Moderna’s getting an added boost as the stock is being added to the S&P 500. Moderna will replace Alexion Pharmaceuticals, which is being acquired by AstraZeneca on July 21. Moderna, which has delivered over 100 million vaccines so far, says it is on track to deliver 3 billion by 2022.

While those are impressive numbers, Moderna’s mRNA-based vaccine may not be as effective at reducing the transmission of the Delta variant of COVID. However, physician Dr. Eric Topol notes that both the Pfizer and Moderna vaccines are 96% effective in preventing COVID hospitalizations and deaths from Delta variant infections. 

Still, the possibility of a COVID-19 booster shot and increased guidance has investors excited. The company is also an investor favorite for its research on a flu vaccine that could enter Phase I testing by the end of the year.

Shares of Moderna are up 275% in the past year. And its addition to the S&P 500 has only increased that rocket ride. (Shares jumped 8% Friday when news of its pending addition to the index was announced.) Its market cap currently sits at $115 billion, putting it ahead of General Electric, Lockheed Martin, and 3M.