A strategy using 4 EMA lines.
The purchase is made when the price is above all lines, there is a slight correction in prices touching the average of 8 periods, this is the time for the purchase. The sale happens in the same way with the price below the average.
Closing happens when the price touches the average of 21 periods.
The average of 48 periods is to check the main trend, so in this way do not execute any order that is against the primary movement.