You can not get fixed returns every day, but it is not impossible to get a 15%:

 1. check Gainers -----> https://bitscreener.com/ some shit-coins High/rise more than 20%. Tracking such currencies may result in your quick profit from these currencies."Do not invest for a long time or lose your money."
 2. Relying on the news: If you keep up with the news, you will be able to win 15% easily and perhaps more based on the news control of individual feelings.
Generally, remember the significant profit needs to take risks.