Nobody can predict when the next boom will hit the market.
That depends on many factors.
Here are the 2 most important ones.
How are the cryptocurrencies regulated and controlled by governments around the world? Will the public digital currencies prevail?
What technical innovations will come in the crypto world. Maybe a whole new coin will come. Will a so-called Altcoin like DASH or MONERO replace the BTC?
As for these altcoins, I doubt they can ever replace Bitcoin. Concerning the next cryptomarket boom...it might start this autumn already, not very soon.
It's very unlikely that we will see a moment of replacing BTC by any alt in the near future.