It would be easy to look at the nearly $1 billion of biotech paper that Wall Street priced last week and declare that the biotech window has been thrown open. But a closer look at the types of deals getting done tells a different story: the fully underwritten market for IPOs and follow-ons remains largely untested.

Indeed, if one includes the $100 million raised by cardiovascular play CV Therapeutics Inc. (CVTX), 100% of last week's $967.7 million in financing came from converts and PIPEs. Converts alone accounted for $800 million of the total.