The collaboration with a major pharmaceutical company like JNJ, coupled with a substantial equity investment, signals strong industry support and financial backing for Rallybio's FNAIT therapy development, particularly RLYB212. This partnership not only validates Rallybio's research and development efforts but also provides financial resources, likely contributing to investor optimism and the stock's sharp rise.

While the collaboration and investment in Rallybio underscore JNJ's strategic interest in rare disease therapeutics and its ongoing commitment to FNAIT clinical programs, the direct short-term impact on JNJ's stock is likely to be more muted compared to Rallybio. This is due to JNJ's larger size and diversified portfolio, which means that individual deals or investments have a less pronounced impact on its stock price.