Well you dont really know for sure but when the candle opens outside the the 5EMA the chance is big that the candle retraces back to the bands. If you wait until it has closed you might already have missed out on your 5 pips.
You could also add RSI 9 with levels 70 and 30 and only sell when RSI is above 70 and the candle opens outside the 5 EMA or vise versa for buy. This will give you a more accurate signal but alot lesser trades.
Forgot to mention though, if the candles rides the upper or lower EMA as in a up or down trend, stay away from a trade until the trend calms down.
Example:
