Sure, that's a good plan for people who want to play in the safe zone. However, most investors are in the crypto market to get rich quickly. 20% might seem good for people who are doing this on the side, but others' plan is, the greater the risk, the better the reward. And cryptocurrencies don't just reach 95%+ profits, in the long run, 1,000%, 5,000% or even 10,000% are not strange to the crypto scene.