I would argue there is no sure thing but.......invest in the American economy. Purchase an indexed mutual fund with a substantial portion of your investable wealth. An index fund is actually America
Keep significant cash, say 15 to 0%.
A market crash is not a market end and is survivable. America prevails.
I envision inflation but not hyperinflation. Even though I believe that America is actually already lost in 2020, do not bet against her.
Thank you.