Has anyone noticed that the Market Depth on the buy side always...

Has anyone noticed that the Market Depth on the buy side always starts building up around 12PM, then someone is holding the price down by placing a big sell order, larger chunks are taken in this locked range. Before the closing bell, the buy side is easing and share price drops back to black by some light transaction. Someone is accumulating at mid 60's. Any idea on who is buying? There was about 150K on the buy side after opening and around 1.3 mil within the next 2hours and this has happened recently many times. It certainly shows an interest in LUM.