[MrMember]

As the saying goes, the markets can stay irrational longer than you can stay solvent. Even if someone can correctly predict a market crash, correctly timing it to make money is extremely difficult. You could go all in on far out of the money January 2020 puts only for the market to continue climbing and then crash hard in February 2020.

[findjashua]

One could keep rolling the puts forward, though it would be a drag on returns if the market stays above the strike and the options stay out of the money.