"first trade of the day ,95% of the time is always house to house ,not sure why ,just an observation :)"

That's the best way I know to set the opening sp.... and perhaps a desired direction of momentum. Houses also get priority over retail in positioning. I called my broker on this once when I has a buy in from the previous day and one of the houses entered there bid the next morning and was placed ahead of me. No reasonable response as to why this was allowed was given. Perhaps someone here would know.