I had the similar experience to yours whilst trading e-mini Dow.
I was also concerned with my sell stop orders being hunted down in an up-trending market.
I have directed a few questions at CBOT people and this was their response:
âMiki - Your experience is not uncommon when trading stock index futures - the tick volatility is high, and prices change rapidly. Market makers have automated electronic market making programs, which constantly chnage their bids and offers as the overall market changes. for example, if the market if 8300 - 8304 , with size of 10x10, and you enter an order to buy 2 at 8304, but the order is unable, it is because the market is changing quickly - nobody can actually see your order, or any stops. I have seen this happen in amny different stock index futures markets personnaly. If you do not like to use 'market orders', but also you do not want to chase the market for 10 tics, you should enter the order in the above example as 'buy 2 at 8308 - if the 8304 offer is still there, you are filled at 8304, otherwise you can filled at 8305/6/7/8 - at least you are not chasing the market. There's an old market saw: " enter positions with limit orders, exit at the market" but for here you can also enter to buy above , or sell below the market.â
Good trading