The Algorithm, page-23

Good buying imo @tamz lucky sod, i'd lime some 12.5's too.
If you are top of the list, no one will get ahead of you at 12.5. What has been trading are 12.7's from the dark pool which are stopping you getting your 12.5 order filled.
The 12.7's sometimes seem to disappear before the aftermarket auction and others get forced to sell into the 12.5's so occassionally some are getting filled but it seems very few. Same with the 14's where 13.7's seem to block.
It's boring yet at the same time interesting
Hope you gradually get the order filled. Thinking you'll be sitting on a handy profit shortly after.