How to achieve stable profits in the cryptocurrency market?
You want stability, but you must accept slower profits.
Two methods:
1. As many answers have mentioned, invest in BTC regularly every month, in spot trading.
2. Use low leverage contracts (5-10x) for BTC. During a sideways market, you can earn 5% four times in one night. Go long after closing a short position and vice versa; it's that simple. Then, after BTC reaches a new high, you can short it directly; it's really that easy.
What you should fear is not being able to resist using high leverage or messing with altcoins.