Bitcoin is the digital currency which is using by most of the countries in the world therefore it has so many benefits beside these benefits there are so many factors which have a good impact over it and that's why bitcoin is highly volatile currency of the world. Like the bitcoin price is more then every thing in the world currencies but the currency system is very strong.
And other reason can also be that Bitcoin and the cryptocurrencies are affected by the news. Therefore, the frequent fluctuations in Bitcoin prices are very common in this market. So instead of worrying, get used to it by updating the news about cryptocurrencies regularly.