Last week's flurry of IPO news, including the largest offering since 2011, suggests biotech companies believe investors are now looking for new stories after pouring money into already public names during the sector's lengthening bull run.

JMP banker Bob Carey said several elements are in place to support the opening of an IPO window, the most important of which is the amount of cash investors are looking to put to work as the sector continues to outperform.