I'm not too sure what the correct term for this is but i often...

I'm not too sure what the correct term for this is but i often notice for some stocks that are highly traded that roughly on or at 4:00 just on market close/pre close that buyers place bids above last trade and sellers place sells at below last trade.

I often think this process is to 'mark the close' but now i see another side of it, almost like buyers/sellers jumping the queue (if you get what i mean) by selling lower/bidding higher to meet each others' trades.

Another way I see it is that, each side tries to mark the close by bidding higher/selling lower and each side puts more or less/just enough to get their way.

Can I get people's opinions on this?