Dax is too big for you. Switch to Eurostoxx, Bund or ES. Overtrading can be also the problem. If you make 10 trades/day, after 3 months your commission costs can add up to 2,400 eur. (with IB's 4 eur /rt). And if you add slippage costs, let's say only 0.5 dax point per trade, 600 trades * 12.5...