I think it's important to note that Bitcoin was only at $170 for a couple of days. When you're zoomed out it looks more like $200. The peak was $1150, which would be closer to an 83% loss.
In December 2017 the peak was $19,600, so if you multiply that by .17 you get $3408, which is pretty much where we are at right now. There's an okay chance that we've already hit the bottom at $3300.
Personally, I'm a bit worried that the SEC will engage in more manipulation with this ETF nonsense. Plus, there will be some Mt Gox things going on in February as well.
Yep, that is true, the exact percents can be tinkered with slightly depending on which data you look at. The overall theme would suggest that bitcoin bottoms sometime between now and $2k though.