Previously, ie before bot trading it was a way whereby you could...

Previously, ie before bot trading it was a way whereby you could guarantee being at the top of the queue of buyers

In your post if the buy had been put in at 1.25 there would have been about 150000 share sold before his were on the market, so if the share price rose at the start he would never have got his shares at the price that he wanted

He also should have bought them at 1.25 ie the selling price regardless of his order request

But since "bots" he will pay 1.375, ie whatever he said he would pay because bot orders rarely if ever appear on the quote list

So basically it is a means to get to the head of the queue but he will pay what his request is usually

This is how I have seen it work but just my opinion