How to distinguish between a bear raid and a selloff? Due diligence! If a sudden and dramatic price drop is not followed by a speedy recovery, then it is a selloff (falling knife), not a bear raid, upon bad news. This happens a lot too in biotech upon a trial failure, an FDA rejection, and so on. It happens elsewhere too, e.g., GMCR nosedived upon a bad quarterly earnings report earlier. That was not a bear raid but a selloff which continues to this day. Any attempt to bottom fish may end up with a falling knife. I have lived through quite a few breathtaking bear raids now. I am determined to catch one if it happens to my stocks again. It happens at lighting speed and it is simply impossible to catch it with live orders. It may or may not materialize so the key is anticipation. That is, to guesstimate the extent of the price drop and enter a GTC buy order accordingly. Even with a GTC buy order, one may not catch it if the set price is lower than the bottom price. Some of my Yahoo group members caught ARNA with buy orders higher than 7.8 last Friday but others with buy order at 7.8 or lower did not get filled.