Now it is evident that Bitcoin price is at an all-time high. Prices have risen steeply, far too fast for my liking. I don't think such a growth is sustainable. The bubble is going to break very soon.
But what is causing such a price hype? I speculate this phenomenon is caused by the increase in the number of Bitcoin users. Hence, demand increases and supply dwindles. Thus price increases. Are there any other factors that could add to this price hype?
Are you talking about the bubble that started in 2010 at $0.10? Dollar parity? Or 2011? Or 2012? 2013? 2014? 2015? 2016? or 2017? Assuming each time is a bubble has been a strategy that makes it easy to miss gains in fiat terms. Every time the price hits new highs (and I think Nov/Dec 2013 was an artificial MtGox created high so there have been plenty of new highs or at least 1 year highs in between) articles and people say "bitcoin bubble" this and "bitcoin bubble" that. Anyone who thought it was a bubble at any of those times and bought (or mined) and held, has done well.
Usage is increasing - whether it is for transactions, "digital gold" wealth preservation, hedging, trading, or whatever. Likewise, new supply decreases at each halving, 1800 new BTC/day now, 900 new BTC/day in less than 3 years. It is simple supply and demand which sets the price at the margin. Sometimes people panic and the price drops from $27xx to $19xx like it did a few weeks ago and the people who panic sold at $19xx now missed out on another $900-$1000/coin. You see posts from people who sold at any point between 2009 and now wishing they hadn't tried to time the bitcoin market.