Depends on the "tick size", just inform yourself first about these details. Maybe broker uses just 2 decimal digits... Of course this is not legitimate when the exchange uses 4 decimals.
If you are serious, you have to upgrade many things. Stop trading from your home. Trade in the trading house with high speed internet speed. Pay rent for the trading desk. Migrate from the free IB platform to high end trading platform like TT. It will cost a few thousand dollars a month for the overhead. There is no short cut. You get what you pay for (or not pay for)
It used to be very efficient before like less than a year ago but now it is bad n sometimes horrible........both for odd n full standard lots.
Really? Lower liquidity and lower trading volumes are to be expected on MAJOR HOLIDAYS which typically lead to wider spreads. Amateurs..good grief.