You cannot use past results to predict future outcomes, this is not your standard stable equities market. Cryptocurrency prices do their own thing regardless of the demand or supply, things just happen. So I disagree that just because we've had some spikes in 2017, we're going to see these multiplied in the future.
Invest in something you believe in, in something that can make a difference. Otherwise you are just betting, in which case reading some analysis is the exact same as picking a coin just because you like it's name (Sia - cause I like the singer).