If the bull market recur periodically, like what happened in late 2017, how long dose a cycle would take? It seems at least longer than a year now..
I don't think that the past experience can be used to prove the future trend. In my opinion, the market in 2017 is very different from the market situation in 2018. We can't because it happened at the end of 2017, and take it for granted that it will happen at the end of this year, which is logically wrong.