With so many of its early years devoted to figuring out RNAi delivery, Alnylam Pharmaceuticals Inc. (NASDAQ:ALNY) had to depend on its investors, who weren't always patient, according to President and CEO John Maraganore. But investors who stuck with Alnylam "thought that we had the right people, and certainly the right IP." Investor FMR LLC has been with Alnylam since its IPO in May 2004, and Novartis AG (NYSE:NVS; SIX:NOVN) has been an investor since its 2005 deal with the company. Both have consistently held more than 5% of the company's shares.

Investors have ponied up $544 million and continue to pour cash into the company. In January, Alnylam raised $185.2 million through the sale of 9.2 million shares. In February 2012, the biotech raised $92.7 million through the sale of 8.6 million shares. At Dec