could drop to zero 
Yes of course , it can drop to zero... and when it will drop to 1 $ I will buy "more" (that's sure).
Hmm I remember the times above 1000$, where bulls told everyone that they would buy a crazy if the price would be again 700$. After the price droped, only a few bought coins, the rest of them just waited for cheaper coins.
The same happens now. No real buying pressure. It looks like 200$ is not particularly cheap...