it's true because every second, minute and hour bitcoin prices are always up and down continuously. and to predict its value is also very difficult. so it's hard to bitcoin in say stable
In every investing have risk especially in bitcoin we know bitcoin is very unpredictable we dont know what happen in there value it's hard to say cause in every seconds or minute it may lose or gain profit in our investment.
Because volatile means the rapidly changing of value and dont have constant value. Bitcoin is volatile because it changes every days, months, and year, its unpredictable because we dont know if it will increase or decrease, but we do know that the value of bitcoin is getting higher and higer every year. And if you want to earn big profit, you just have to be patiently wait for its increase.