As of yesterday's close(I put these in a table, but am not sure it will be depicted as such by the software here):
Alnylam $5.8 billion
Arrowhead $891 million
Benitec $140.9 million
Bio-Path Holdings $379.3 million
Dicerna $656.8 million
Marina Bio $ 20.8 million
RXII $ 62.3 million
Tekmira $364.8 million
These are all exogenous RNAi plays except Benitec (ddRNAi) and Marina (ddRNAi encoded by bacterial DNA). Valuation of all must be taken in the context that we may be mildly in a biotech bubble, so vast and deep is the speculation. I feel RXII is appropriately valued because of its paucity of clinical ideas....RNAi notions, but no clue what disease to go after. Alnylam is heinously overvalued now.
I regard Arrowhead and Tekmira as Benitec's most approximate peers in terms of technology and clinical stage of development. So, Benitec is still undervalued. I am waiting for a pullback to load up on shares again.
I have left out of this analysis companies that are making locked oligonucleotides (like miraversen and etiplersen) to go after microRNA. I feel those are a different beastie.
Disclosure: I am long BNIKF.