Bitcoin's bull run of 2017 pushed the market to huge destruction from the peak to bottom. Panic, rumors, exchange hack etc news totally played in inverse role. Many tokens ruined, maximum altcoins touched the lowest point even Bitcoin reached to the previous bottom point but recent bull run didn't pushed the market to such decline rather it showed a sensible behavior which took small correction that is helpful for building the physical level of the traders. That's the difference between the two bull run.