Bitcoin cannot crash nor go down against the dollar. You can print as much US dollars or fiat currency as you want. BUT YOU CANT CREATE MORE THAN 21 MILLION BITCOINS. If everyone just realize that fact, it would never stop going up. It seems like the idiot stupid fools that are selling since December don't know that. It is just as simple as that.
That's why the tulip bubble argument against bitcoin is flawed at the beginning. They keep on comparing bitcoin to tulip bubble were there is unlimited supply while bitcoin can't go beyond 21M coins in circulation.
And it really boils down to the basic economic law of Supply and Demand. Only please take note that every 4 years, there is a halving making the supply of bitcoin scarce, and the price could increase overtime until a final quantity of 21M bitcoin have been mined.
Just because there is less of something doesn't immediately point to the fact that it's going to be expensive, that's just one of the many factors which should be going into a valuation. -- At the moment I do think that bitcoin is a tad bit overpriced, and its too volatile for people to actually use it (as the main purpose of being a currency)
So yes bitcoins price can go down, but it shouldn't change the actual tech or anything else (being usage) behind bitcoin -- if the bitcoin price was to stablize though that'd be amazing of for the bitcoin community as adoption would increase.