I agree, truly fantastic work.
Instead of having the bot pull fixed parameters from the config.js, would it be possible to adjust it so it also accepts parameters via the command line?
And would it also be possible to have the bot auto-append the profit report results to a .csv table, along with the settings used?

Something like:
node gekko --EMA1 10 --EMA2 21 --buy_threshold 0.25 --sell threshold -0.25 --fee 0.6 --output results.csv

That way you could cycle through different parameters very comfortably via a batch file and find the optimal settings.

Edit:
it would be even more comfortable, if there was an option to set upper and lower values and an increment for each parameter in the config.js

Example:
buy_threshold_upper 0.5
buy_threshold_lower 0.1
buy_threshold_increment 0.01
output results.csv

The results of each iteration could be written to a table like this:
buy_threshold sell_threshold amount_of_trades simulated_profit
0.50; -0.25; ...; 200; 1500%; ...
0.49; -0.25; ...; 210; 1510%; ...
0.48; -0.25; ...; 220; 1490%; ...
...
0.10; -0.25; ...; 200; 1200%; ...

Of course, the more variables there are, the more exponential grows the number of possible iterations, I'm aware of that.
But it would be awesome ;-)