The main difference between the current and 2014/2015 bear market is that right now we don't have MtGox to worry about. I'm certain that if MtGox didn't collapse back then, the low in 2015 would be far above $150.
why?
people drastically overestimate the importance of mt gox. i was part of multiple trading communities, and pretty much everyone had aready moved to bitfinex, bitstamp, btc-e/mt4, chinese exchanges (okcoin, huobi, btcc). most traders left because gox had already been having fiat withdrawal delays for many months.
they had far less share of world trading volume than people say. the scope of the BTC losses were due more to gox being used as a massive online wallet. and remember, the gox collapse locked up lots of available supply. everyone who lost coins had to buy back whatever they could.
MtGox gave the bear market extra fuel to keep thriving, which looking back, was the best ever "recent" buying opportunity. I don't think think we have to wait another year to fully bottom out.
i dunno. gox collapsed in february 2014. the market bottomed in august 2015. i really don't think it fueled the bear market for 1.5 years. that was just post-bubble supply and distribution. the same thing is possible now.
Market bottomed in January 2015. Then it went sideways until October when bull run started.
2014 bear market was longer then wil be now from simple fact that bull market of 2013 was stronger then 2017. You had sort of 2 bull runs in 2013. in April and November.