I think it was just a coincidence that it was getting stuck at that price. It will move off of that once the price rebounds again.
Eh, it always seems to get stuck at numbers like 420 too. I think some people place buys at those numbers just to laugh at the chart, or think its a lucky number to go in at or something.
The bitcoin price is about $590 at the moment. So it is not stuck at $420. I think it will rise to $600 soon.