RE:RE:Acumen bought 978000 shares todayYes.
It only tells us trade volume by different brokers. Some of the institutions even hide the broker name & number by using Anonymous.
With the help of electronic market book, individual executed data & house position one can figure our accumulation, sale or high frequency trading from a small spread.
Sometimes one can figure out where the short position came from. You can take the 2 week short position & see who the large sellers were during that period. It is mostly guess work. It becomes easier if the short position is large.