Can you provide more detail about this? There was another post here that mentioned pinging the order.
The same issue happens in Futures as well but your much better off staying with futures when it comes to execution of orders.
Pinging - Sometimes people will see a big offer and will buy a few to see if the guy runs and all the offers go away or if its a legit order really willing to sell. Spoofing is illegal but it still happens all the time and the exchanges have resolved the issue by charging them a fee for every order so they keep quiet. It's only a problem when we have a flash crash and the politicians want a scape goat like that kid trading in the basement of the parents house in the UK. They have him locked up in a jail in the UK pending extradition to the US to face charges that he brought down the US financial markets in 2010. He was putting in large sell orders which he removed as soon as buyers came in and started nibbling. So he got short and put huge sell orders in and the market tanked, once he was up 10 Million, he bought back his shorts and then removed all his sell orders and then supposedly the whole world stepped in and bought the shares right back up to unchanged on the day....and we are suppose to believe it was his sell orders above the market on that one day vs every other day where he did the same thing, had brought the whole financial system to it's knees.... now we all know that the order book itself is only looked at by algo's and the rest of the world don't even have access but whatever.... they got him in a bright orange jump suit already.
