1.) The stock market is no different than the dog track - only gamble money you can afford to lose.
2.) Squirrels never put all their acorns in one location to manage risk - spread funds across institutions and asset classes to manage instiutional and market risk.
3.) Risk tolerance is partly emotional - do what helps you sleep well at night. This will change with age, health, and retirement status.
4.) Keep some "petty cash" on-hand in case of a disruptive Black Swan event, i.e, like ATMs, and Credit Cards not working.
Because of automated algorithmic trading (computers), the Market will melt up, and crash down. When the crash happens, you may not be able liquidate (sell) your investments as quickly as you'd like. In the event of a Black Swan event, institutional orders take priority over individual orders.
I recommned meeting with an estate planner to help you structure your assets to protect in case there is a need for assisted living or a nursing home.
Was 9/11, 2008/2009 Financial Crisis, and Covid part of most people's retirement planning? Nope.
My in-laws' retirement was thrown curve balls with health issues - Cancer (in remission), Alzheimers/Dementia (progressing), Congestive Heart Failure (being managed with meds and a pacemaker/defib), C.O.P.D. (managed with meds and respiratory therapy), and emergency intestinal surgey (recovered). They've recently met with an estate planner to help structure their legal documents to protect their hard-earned savings and investments.
When the Big Flush happens, most people will be in the same boat. Work with trustworthy professionals to make sure you have a lifeboat and a life jacket in case the ship goes down, or the rescuers are slow to show up.
I don't know what will happen, but, whatever is happening, I still need grow my savings and investments while being able to sleep well at night.