closing price, page-69

Not sure what you guys are thinking, but my thoughts are that we have possibly four BOTs working HTX at the moment.
Below are the last trades that have gone through.
17.5 15,000 11:34
17.5 10,000 11:34
17.5 30,000 11:34 XT
17.5 6,934 11:34 XT
17.5 6,466 11:34
17.5 3,303 11:34
17.5 3,297 11:34
17.5 76,703 11:34
17.5 1,957 11:29
17.5 1,624 11:29
17.5 1,521 11:16
17.5 1,621 11:16
17.5 62 11:12
17.5 62 11:12

There is the
1) 6466, 6934
2) 3297, 3303
3) 1521-1957
4) 62

Why would anybody who wants to buy, buy at 18 when if the wait in the queue one of the bots will sell down to them.
I can't see the point is BOT traders selling their shares without buying more at the same time - unless they are waiting for funds to become available and so in the meantime they just keep the share price in a holding pattern.