We can only predict based on coin market cap, since there has been some recovery this year of its recent fall in 2018 but no one actually knows when the next bull will eventually commence.
Following coinmarketcap definitely will lead to miscalculations as most of the top crypto currencies are highly manipulated with their circulating supply compared to how bitcoin is still the number one coin in coinmarketcap list.
Regardless of when the next bull run will be happening, it is always good to buy some coins when they are available for cheaper prices. Considering this, we should react right now for buying more coins before it will be late.