A system to catch big moves

[twoti]

Hi all, I am a newbie in forex and have been testing out this system that I found until I felt that I may need some help.

I use,

Macd (9,26,12)
Stoch slow (14,3,3)
Adx (14) with a 20 trigger line

I have been using it on Gbpusd 30min chart.

Entry conditions:

Buy when
1) Macd just cross '0' line
2) Adx is above 20 line
3) Stoch in overbought region (above 80)

Reverse for Sell.

Notice that after all this triggers form, the market usually trends huge in the direction.

The catch is I need help on the stop loss and exit. Can any kind soul help me on this?