Trading logic

[asat232]

Help me please to understand trading logic.
I'm using type=SYMMETRIC
When "buy" order is filled and filled_price < last_price (where last_price is the current market price)
https://github.com/PyWaves/BlackBot/blob/master/BlackBot.py#L200
So, placing again "buy" order at same grid level, which just before was filled.

The same concern about filled "sell" order, placing again "sell" order at the same grid level which was already filled
https://github.com/PyWaves/BlackBot/blob/master/BlackBot.py#L205

Thanks a lot for your help.