Moderna Stock Plunges 18% After Historic Cancer Vaccine Rally

Shares of Moderna (NASDAQ:MRNA) plummeted by 18% to $142.70 in midday trading, a sharp reversal from its historic 177% rally on Wednesday.

The decline follows the company's announcement that its personalized cancer vaccine, intismeran, hit its primary endpoint in a Phase 3 trial.

Moderna and Merck (NYSE:MRK) co-own the pivotal trial, but their shares reacted differently to the news. While Moderna's market cap of $56.18 billion was reshaped by the result, making it a credible oncology franchise alongside its infectious-disease base, Merck's shares barely moved.

BioNTech (NASDAQ:BNTX) also fell 4% to $108.39 after its own read-across rally from the mRNA oncology platform.