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.
Do not forget that BTC market or any criptocurrency market has a lot of speculations. It can't be constant growth without corrections at any market - some people want to buy and some people want to sell coins at the same coin price.