Envelope strategy conditions 

Envelope indicator with period 20 and deviation 0.1

Moving Average Moving Averange (MA) with period - 6.

Chart period - 3M

Trade term - 30 minutes

Price growth forecast

As you have already guessed, the price should go beyond the boundaries of the envelope, but you should enter the trade only when the moving average crosses through the bullish candle. This is a very good filter.

Price drop forecast

Everything is exactly the same here, only the price should go beyond the upper boundaries of the envelope after an uptrend.