I was wondering about the the functioning of the bankroll: is it possible to keep track of investments/divestments in/from the bankroll by taking as reference two distinct moments, t1 and t2 for example, and comparing the difference (bankroll_t2 - bankroll_t1) with the difference (investors profit_t2 - investors' profit_t1), in the sense that in the absence of investments-divestments the differences mentioned above should coincide? or are there other variables at play?
Assuming I understand your question right, yes. If there are no investments or divestments, then the change in the bankroll should match the change in investors' profit. For what it's worth and in case you didn't know, you can find detailed information on bustabit’s bankroll balance, investors' profit and more at
https://dicesites.com/bustabit.