I'd say there you shouldn't wait for a bull run in 2019. Not until 2021, that is.
If you can just speculate with the crypto because this is what is seems to be doing this whole time (Q3 and Q4 of 2018 + Q1 of 2019).
2021? I guess you must be joking mate, I dont see any Analysis, news or speculations pointing towards that year you mentioned, everything points to 2019/2020 so I really dont know where you got your own theory from but personally, I believe most coins are gradually heading towards another BULL RUN again this year.
My little advice is that we should try as much as possible to also always promote more of positive news about crypto currency if we want crypto currency to really appreciate, aside the whales manipulating the market, one of the causes of these bearish trend is bad news because it end up scaring investors away.
I believed he got his prediction base on how the market was badly affected with how long the market correction and bearish trend existence in the market last year till now with the inclusion of the panic level of crypto investors and absent. But, he dont things dont work like that in crypto market.