My idea is very easy!let me take about it! it's a simple GRID SYSTEM
for example:
1: buy 1.9000,if it up to 1.9020, go on buy 1.9020, if it up to 1.9040,go on buy 1.9040. DON'T CLOSE BUY ORDER.
2: if it form 1.9040 down to 1.9020,so close all buy order.
3: open new order to sell 1.9020, if it down to 1.9000, go on sell 1.9000,if down to 1.8980,sell at 1.8980. DON'T CLOSE SELL ORDER.
4: if it forme 1.8980 up to 1.9000,so close all sell order.
5: 1 to 4 circulation.