It wasn't a surprise because bitcoin was close to $50k price for a couple of weeks but will it be stable there ?
During the next week will the price be heading downward because of sellers making profits or is it going upward when the next price to generate media interest will be $75k ?
It's difficult to work out if it's going to stay stable at $48k - $50k
Doesn't this topic belong in "Speculation"?
Yes, the price is sustainable. There is only so much bitcoin and people place value in it. Any price point is sustainable.
However the price isn't guaranteed. We've seen huge crashes time and time again, so who is to say we couldn't get a 90% crash this time.