For me, the most common mistake is "Cryptocurrency is a market for get-rich-quick in which everyone can earn an enormous return without any knowledge on trading"
I have seen so many people jumped in the market with hope for just a get-rich-quick by just buying random coins. In a young and easy-to-manipulate market like cryptocurrency, superb trading skills are required in other to earn from the market. There is no such thing as easy trading or get-rich-quick here. It's all blood and sweat to earn here.