it reduces most of the big drops, but not all of them, sometimes it does not work, and worse, it sometimes causes an exit after a big drop. Maybe it happens only once every 50 or 75 years, but if you hit that "once" at te wrong time, you could be very negatively affected financially for the remainder of your life.

There is no way to a survive the end of the world.

There is plenty of evidence & claims that big sharp drops are like potholes that recover pretty quickly.

For actual bear markets, they start slowly and give you plenty of time to get out.

Ken Fisher famously says that the first two-thirds of a bear market usually accounts for about one-third of the total percentage drop, while the final third of the bear market accounts for about two-thirds of the drop.



So I have to think about using the typical 30-year investing horizon at this point. Maybe I should be using 25 now?

Nah, 25 is essentially the same as 30.

It is once you get down to looking at around 5-10 years of life expectancy that it is reasonable to be hyper sensitive to bear markets. Because you may not live long enough to recover from the bear.

The secret to ride out this is to have a large large portfolio, so that even a 25%-35% drop won't change your standard of living.