I don't think it was only 35k worth of BTC that caused the crash in price, as acidyo stated, Chinese NY, FUD around regulations, Scams like Bitconnect, FUD around futures and the Issues with Tether all culminated at a point where BTC was at an ATH and an attractive sell point for many hodlers.
In my opinion it is great that BTC held 6k and held well above where it started at jan 2017 with all the selling that happened, all that selling is out of the market now, all the FUD is priced in and BTC held 6k and bounced to 12k doubling, it's only natural that many who bought the tops and bottoms over this wild price action will take their profits and losses or break evens as everyone has their own game and view points here.