You obviously do well out of it but that comes through...

You obviously do well out of it but that comes through experience in knowing how all the players there work over time.

The other thing that sucks about it for retail punters is the delay of 3 (4?) days for data. A lot can change in that time when big players make a move and retail is usually the one left holding the bag. So whilst the data can help form a view of a likely play building, you really do have to watch the chart like a damned hawk to see when the worm turns and be out the door or in the door 2nd after them.

This is of course only an issue for intra or day traders. I find broker data useful as a medium to long term investor to try and work out who was doing what at key points in a chart's history to get a feel for where it may be headed after I am happy with the financials/outlook.