You only have a loss when you sell a security. So if you are interested in needing to be able to sell securities in the next 3 years, then invest it in a security that will not lose value in the next 3 years, such as bonds or FDIC insured accounts or cash. If you are not selling in the next 3 or 5 or 10 years, then historically, equities do not lose money that far in the future. The further out into the future, the lower the probability of loss.

So you “insure” yourself by making appropriate investments for the appropriate time horizon.

and I'd be interested to compare performance of both approaches (probably you're right, anything else is too difficult or expensive for retail investors and doesn't give extra return)

thank you for the exchange so far