Progress on the algorithm but ...

I found a technical indicator that works better than MACD on the tests I've done so far. It's call RSI (Relative Strength Index):

It doesn't generate as many trade signals as I had with the MACD test, and it does show a profit. BUT the profit only comes after a too-large drawdown of the account (over 60%) in the middle of the backtest sequence.

More research is needed! I'll update when I learn a bit more about the next step.