Not arguing amateur or pro act but it was a certain type of day trader job. They responses on bio company news and associated moves - get in and out quickly with whatever profits. They don't need to know about company neither magnitude of the data. Based on the same day trading pattern, they waits following day and make appropriate call.
This morning case, ~87k shares got out at once that brought down 2.09 to 1.86 range and follow up small trade (1.3k) brought down all the way to day low 1.82. This created buying opportunity for others.