I want to get a steady return every year, around 10%-15%. Is it better to mine or buy ?
You can't sustain it if you choose mining. Expensive equipment are needed to facilitate your own mining farm. Buying is a better option but the percentage of return is unstable and it can reach or can't the given numbers.
What kind of cryptocurrency do you guys have? How long have you been holding?
Bitcoin, the all-time high has passed and the bear market of 2018 yet still I'm holding.