The strategy based on the price breaking out of a high period Bollinger Band and then coming back into the bands.

For short trades: Wait until the price closes above the upper Bollinger band and wait for it to close below the upper band. Then go short with 1 ATR stop loss and 1.5 ATR take profit.

It can be used in any time frame but I recommend 15M as its rare that the daily or 4h will break out of an 800 period Bollinger band.

The library file Util.mql4 is used for determining lot size and checking if a new candle has opened and validating lot size.