Today, at 3.30 pm Eastern time, I had placed a buy stop limit order for the Russell 2000 futures contracct. It was a buy stop limit order with stop price 709.50, and limit price 709.50. The market traded through my stops, at 3.36 pm, but IB failed to execute my stops. The Time and Sales (at that time) printed trades at 709.40, and then 709.60. So there were no trades at 709.50. But IB's execution logic should have stopped me, correct? Of course, I can always place a buy stop order, instead of a limit order, but I'd like to limit the slippage. Can IB or anyone who has noticed these issues clarify what type of orders to place to ensure better fills, executions and control slippage. Thanks.