There's no better time to buy than the current. In any situation. This is true if you believe in the technology. If your aim is speculation, then good luck: you will win some, you will lose a lot. Just go for coins that have great ideas, for instance, the Eterbase project. Eterbase will feature an exchange that will have proprietary low-level, high-speed matching engine that has low latency at the core of the exchange's architecture.