Moderna’s Billions: Will Building Big Before an IPO Pay Off?

When Merck invested $125 million and deepened its ties with Moderna Therapeutics last week, it was more than just an evolution of the relationship between the two companies. It continued a high-stakes strategy by Cambridge, MA-based Moderna and its backers, and made them a case study for a rarely used method of company-building in biotech: staying private for years while building big.