India, Aug. 19 -- Moderna's stock is soaring after major cancer vaccine news. Moderna and Merck said on Wednesday that their experimental personalized cancer vaccine showed positive results in its first-ever Phase 3 trial. The news pushed Moderna shares up more than 120% in morning trading.

Merck's stock also jumped sharply. Merck shares rose more than 10% after the companies announced the trial results. The huge move in Moderna stock is linked to the size of the two companies. Merck had a market value of around $333 billion before the jump, while Moderna's market value was around $25 billion. This means the same positive news can create a much bigger percentage move for Moderna, according to CNBC.

The cancer vaccine is being developed ...