You can make 10% daily, depends on your luck though, mostly.
It's not depend if you are lucky but i think if you have knowledge and skill to trade what exact coin that you want to trade. Actually, even 100% you can make that profit if you know how it works, but it takes time before you master that skill.
You can make 100% or even more % profit in a day but the question is can you make it consistently same every day? My answer is NO, even for expert traders.
Because not everyday coins will move up or down, so some days you can make a good profit and some days you need learn to book losses to avoid more losses. No one can make a consistent profit in trading.
100% consistently in a day is not possible but 1% in a day is very possible even if you put all the stop loss and every other thing in check. That is a low amount compared to what I make from trading every day. As long as you are very vast with trading and you have the knowledge on how to play safe, this is something that you can always achieve.
That is like the OP saying 30% in a month, when i can make that consistently in a day or two except if there is just no coin showing some sign of movement within this period.