MTS: Original MACD From the Book

The model is straightforward as following, while the original text is attached at the bottom:

Long Entry/Short Exit:
DIFF crosses above DEA, and DEA>0.
Short Entry/Long Exit:
DIFF crosses under DEA, and DEA<0.

The logic is very simple and straightforward. A bit of more explanation is here. MACD is a “Moving Average” system, which calculates EMA(12), EMA(26), and then derives divergence and convergence based on the gap between the short term and mid term average lines.
DIFF=EMA(12)-EMA(26), which measures the gap.
DEA =EMA(DIFF,9), which checks the average of the gap.
If DEA is above 0, then DIFF has remained positive for some period, suggesting bull in the play. It will be good to open LONG to ride the bull trend, while it is fair to time entry when DIFF is crossing above DEA.
If DEA is below 0, then SHORT action would work similarly.