DAX Breakout strategy

This is the strategy I have been using for the past few days and it proving to be my best yet. I use no indicators at all.

I assess the range from 07:00 to 08:00 GMT and plot the high and the low. Using 5 minute candles I wait till either of the extremes are broken and the candlestick closes below the low or above the high. Buy the break of the high, sell the break of the low. If neither extremes are hit within the first thirty minutes of the open, ie by 08:30 GMT all bets are off. Any views from any other open breakout strategy traders most welcome and any tips on other indicies / fx crosses they might use?

It's a familar principle. Where do you personally set your exit?

DAX Breakout strategy ... sounds stupid, but please explain in detail

i.e.
>>> I assess the range from 07:00 to 08:00 GMT and plot the high and the low.
Are you analyzing the last official trading hour of the stockindex dax in the evening ?

I tried similar strategies on DAX in the past and they seemed to barely break even over extended period of time. Don't want to discourage you too much, just saying that breaking inital high / low does not guarantee anything.

Its better to wait till about this time of day. Take the range over the opening 0.5 -1hr then watch for direction till mid morning, re assess / add to till lunchtime, same afternoon. Never hold overnight unless very good reason why the market should be opening even higher/lower the next day. See the range now is close to a rebound/break level Dax Live Chart - Deutsche Aktien IndeX | Stock Trkr Trading Resources

Backtest and optimize would be nice

but how?