RE:RE:Big drop" Who/why does someone sell 300,000 shares??? "
No way to have a certain answer for that question, but the only house that has sold >300,000 today thus far is "Anonymous" (the actual name), which is aptly named, to provide opacity for the actual entity make use of Anonymous to hide their trail.
It's primarily used by institutions and/or power players, though, and they generally have many possible reasons for buying or selling stocks, since they will generally have a lot of different bets on the table at any given time.