I've noticed that people use the term 'slippage' now in a vary vague sense... so depending on whos talking it may mean different things. Generally, this happens is illiquid markets, when say Renaissance used to purchase S&P Futures a generation ago, the price would slip away from them because it crept higher by sucking away the lower priced sellers (no place else to go but up).
5% is huge and nominal is even more, diversify I would say, look some other broker too along with existing one.
I do to an extent. I trade index futures and usually try to move my stop to a quarter point over entry first chance I get after the price has moved in my direction so as to pay my commissions if it moves against me. I let it stop me out because I can always jump back in once I size up the price action again. As far as actually tracking it I do not. I just make the best play I can and adjust as I go.
If I am not wrong, slippage is when we requested to get our order filled at a certain price but because of the market moving, it gets filled at some other price. Sucks when that happens!
Yes, it sucks. I quit a broker for this reason, always killing me with deadly slippage. This is common with MM brokers. True ECN brokers offering stock is best option for me. Stock and news trading with Forexchief is good. No killer slippage.
In with MO. Out with LO (daytrading) Built into the expectancy of the system. No way around slippage. Increasingly negated by increasing timeframe.