So wait 6 months after the market tanks then start to drop money into Long Positions every month(Where you make a profit when the market finally goes up)?
Edit: People here don't know what short and long means in the stock market.
The market fairly valued would have the S&P 500 Ratio around 15.
Right now it is 25.
So, based on that the S&P 500 is 166% overvalued and you are overpaying to currently buy the Index.
However, the S&P 500 could go to 200% overvalued in the near future...or drop to 100% or less.
Eventually the Index will drop to 15. It always has. The exact "when" is unknown but it will happen.
How much risk you are willing to take depends on how soon you need your money.
I think the best idea is to consider if you can withstand a 50% market drop in your equity values.
If you can then no problem to stay invested. If not, then you should adjust your positions to where you can withstand such a drop.
Just like gambling. Don't bet more than you can afford to lose.
(Cash and Cash Equivalents + Bonds) + 1/2 Equities = Safe Zone for Black Swan Event
You can be 100% Equities as long as you can withstand a 50% loss.
A Black Swan Event usually is what leads to a crash.
Unfortunately, no one sees the actual Black Swan Event until it's too late.
https://www.multpl.com/s-p-500-pe-ratio