I'm almost sure we had what is called a "Gamma Explosion" in the options market for Questcor. Potential buyers during the trading day saw steady declines so were reluctant to buy and stop loss orders did the rest of the damage.
I think its safe to say its a good time to accumulate.
Not until it settles down and shows it has bottomed. Regardless of fundamentals, which obviously don't matter much in QCOR case, the MM's and HF's seem to be able to take control of this stock at their whim and do whatever they want with it.