Firstly you got the bitcoin halving coming up, which has historically meant that markets are bullish for at least a year after the event. BTC being bullish will also drag the rest of the market up along with it, analogous to how a rising tide floats all boats.
Then you got the ETH hard fork, which could turn out to be a positive development. It's not guaranteed, but I do think that it could have potential to affect the entire alt market positively.
Historically, the heat of the bull run hasn't come until a few months after the halving. There's usually a slight price increase leading up to the halving and then it really starts to take off from there. That trend has held true so far with the price 100% this year. I really think that history will hold true and we will really start to see this thing take off after the halving in a few months.