Rumors swirl about an AstraZeneca and Gilead mega-deal—but it doesn’t make sense

Nothing gets biopharma investors’ blood pumping quite like the rumor of a massive corporate marriage—especially when it involves two of the world’s most prominent drug makers.

On Sunday, Bloomberg reported that the British drug giant AstraZeneca had approached California-based biotech Gilead about a potential M&A that would amount to “the biggest healthcare deal on record,” per the publication.

The companies have been mum on how true those claims are. AstraZeneca and Gilead had not responded to Fortune‘s requests for comment as of press time, and this post will be updated if they do. Such a deal, however, would be undeniably