first 300% per month is not impossible but the possibility of loosing your money is much more , because gaining that much means you need to take 300% risks , in this bearish market that bitcoin has broken 4000$ that is almost a dream to make 10% per day , sorry!
actually calculating fixed profit is very unlikely, market factors that are always flexible greatly affect mentally, sometimes there are coins that do not even make a move at all in 24 hours so that if such, the coin has a tendency to dump