Has anyone noticed what goes on with the sell side every...

Has anyone noticed what goes on with the sell side every day?

Before the market open the sell side for example could be 10m and then when we open it goes up to say 11.5m, it will stay about this level throughout the day and then before close it will come back down to the morning amount.

It is one like someone is stacking the sell side throughout the day and then pulling before close. This has happened every day for the last week or so.

So to me it seems like someone is trying to put some sell pressure on the price by simply inflating the size of the sell depth.

P.s. One of the slowest opens I have seen for a while! 10k at market.