In my opinion, SP500, Dow and co.. in general the economy will crash in 2019, in addition to that a war or big revolution will happen
SP500 is running out of steem, the SHS formation is almost complete, and broken downwards.
I think is will cause a bear movement over the next months with a crash happening.
In countries with econimic problems and revolutions like in Venezuela, Iran and other countries the price of Bitcoin and interest in Bitcoin is skyrocketing. Also Bitcoin was a reaction for the big economic crisis in 2008/9.
So Bitcoin is reacting antiproportional to the nations economy status. Western companies and the western economy makes a very big part in the world wide economy. If a crash happens there, a very big money flow will happen into Crypto.
I think that will happen in 2019. I see the SP500 and in general the western economy crumbling. Revolution in France, Brexit.... and other crisis will hurt the economy.
Disclaimer
This is all my personal opinion. No professional advice. Everybody trades on their own risk and is responsible for themselves.
good luck