There are several factors which can cause bitcoin prices to rise, which include: psychological factors, political risks around national currencies, specific rules in several countries, governance of bitcoin and its innovations. But for now, bitcoin price analysis shows that positive media coverage is one of the main factors, which drives the price of bitcoin to rise again.
You probably forgot the most important reason about why the price of bitcoin goes up from time to time, this happens with each new update and advancement of the technology, we saw this in the previous year and every time a major upgrade is done to the bitcoin network then the price of it will go up.
Continuity of the price depends on regular demand and investment capital. If more and more people invested in bitcoin, the price will grow more but if there are no buyers in the market, the price will not increase. It is natural and if you see big bump in the price without any investments, you should understand that this is artificial and will be corrected after some time.