The REASON an investment firm buys more of ANY stock is because of Fund inflows. IF you could determine if Blackrock for example had increased the "weight" of AVXL within those products....THAT would be significant.
However, that is not the case (while I can not validate that assumption).
As to the "stability" your point is well made.....so long as the Macro Market cooperates with investor inflows, or more precisely lack of withdrawals. Bets being placed as we both type whether the Economy will lead to the exit of investor commitments. Spec Bio is likely to be one of the first sectors.
we've been taking beating with the rest of the market/biotechs for the last two months since the cc early february (missling effect??)... maybe the markets and especially biotechs find their footings post fed. but otherwise, seems like more beating until a good, meaningful news