I prefer 1% to 2% a day because it is more realistic than 20% to 30% a month which is also hard to achieve in today's market. If you are a day trader, you can earn up to 5% depending on your strategy, familiarization and knowledge in trading. Besides, 2% rule is very effective in trading and will minimize your losses and gains at the same time. You can watch it on youtube or search it on investopedia website for you to get more information how this rule works.