I've been studying for a while the market history. The "time in the market" saying is true; if you get the US stock market 200-year average, even the 1929 crash feels more like a correction than what it really was. 2020 is just a blip in the bigger scheme of things.
But we all aren't likely to even see 2100, so our time in the market isn't that great. Some of those blips are huge things for a single lifetime, hence the question. At what point a correction and a "fasten your seatbelts" scenario actually becomes a general disaster that will ruin a lot of people and take years to recover?
For example, all the signs in April would point to a major downturn in the following months. Seeing it now, in the end it was just a small bump on the road. Even in the pandemic, everyone was somewhat able to foreshadow the shit hitting the fan (the S&P 500 began to fall down in mid-late february 2020, and we all were seeing huge news everywhere since december 2019). Anyone with a minor glance of the news could see what was likely to come in the following months.
Now in 2026, everyone is talking of AI bubble, another global recession in the likes of 2008, an apocalyptical disaster scenario where everything starting falling from the sky.
But for someone investing, what would be the line (or zone) between keeping the stocks during a poor month, and outright selling them all to avoid being hit by a crisis? What could be the next triggers for it to happen?