Was Moderna Stock's Cancer Vaccine Run Visible In Advance?

Moderna (MRNA) stock rose roughly 510% over the year to September 21, 2026, climbing from about $25 to about $173. The S&P 500 gained 18.5% with dividends reinvested over the same window, and Pfizer (PFE) about 23%. The run's central event came on August 19, 2026, when Merck and Moderna said a Phase III trial of their cancer vaccine, intismeran autogene, met its endpoints in melanoma. A rough timetable for the trial was public long before the stock moved, but its result was not.