If VRUS was worth $11 Billion, is it unreasonable for ENTA to be worth $5 Billion?
Not a proper comparison. VRUS owned the full worldwide rights to Sovaldi at the time it was acquired, while ENTA has licensed its main asset, ABT-450, to ABBV in return for milestone payments and a royalty stream on a portion of a 3-drug regimen.
VRUS, when it was acquired, was not as far along as ENTA is now.
True, but this is outweighed by the point mentioned above.