I don't think it fluctuates more than some fiat currencies because this volatility has been there from day one just like my local fiat which has such high fluctuations too. This has been on going for the past 8 months after the halving. The reason behind bitcoins volatility has to do with people's growing interest and the panic sellers. Those two seem to be occurring every now and then so it keeps taking all of us for a roller coaster ride.
But panic selling would bring the price down, isn't it ?
I mean the more orders getting filled at cheaper price would mean less orders at a higher price and hence a low overall price of bitcoins.
Growing community hasn't played all that big part in the rise and change of price because you see the price almost doubled up and the community hasn't even grown 25% in this much time as compared to original community. Maybe there are some big investors in bitcoins that have caused such a rise ?
You are quite right said. Such manipulation of the bitcoin courses are held group of users who have a large number of bitcoin and they especially do bitcoin price fluctuations on the market, then to be able to earn on the difference in price.