not sure what OP meant, but depending on what your retirement account looks like, control wise, you can "rebalance" your assets to the lowest risk funds. generally those include money market funds, which are highly liquid and tend to only "grow" at or under 1% and their management fees eat even a piece of that. they have pretty strict requirements of diversification and the asset classes are all shit like currencies, treasury bonds, short term secured loans, etc. i think even during the GFC 2007-2008 it was a huge deal that some of the money market funds from banks that went under dropped 2-3% during the crisis and that exacerbated panic since these funds aren't supposed to "break" (decrease in value at all) even during a total shitshow. my understanding is that part of the treasury / TARP bailout was to cover that 2-3% loss even. of course, if congress ever did the thing where they let the government default, that would probably make those funds go haywire and probably induce a coup because the capitalist class relies heavily on treasury bonds.

one could try to actually cash out early, but the taxes owed on early disbursements from retirement accounts are generally prohibitive since retirement accounts are built around deferred taxation. so you basically take a lot off the top if you do that.

anyway, all this assumes like the dollar doesn't become worthless or there isn't a revolution, because then all bets are off and what would a bag of cash in hand be worth then anyway? more or less than a bag of potatoes?