Moderna Stock Surges 177% After Positive Melanoma Vaccine Trial

Moderna's stock price surged by 177% on August 19, 2026, after the company announced positive Phase 3 trial results for its personalized mRNA melanoma vaccine combined with Merck's Keytruda.

The shares jumped from around $51 to roughly $140, adding $45 billion to Moderna's market capitalization and lifting it to approximately $55 billion as of August 31, 2026.

This sharp rally is being driven by investor confidence in the long-term oncology potential of Moderna's mRNA technology, which has been demonstrated through its success in preventing recurrence and spread of melanoma in high-risk patients.

Despite this optimism, analyst consensus remains cautious, with an average 12-month price target of $80.53, well below the current share price of around $137.99.