Depends to what end? SHTF nuclear/zombie war probably tradeable first line necessities of some sort. WWII occupied Soviet territories gold,diamonds etc bought you a lot less food vs medicine, tools, ammo fuel Get out of town fast due to some localized disaster cash will work just fine. SHTF scenario initial stages assume either a) you'd have what you need for self sufficient survival or b) you'd be getting what you need at gun point and you'd have to be comfortable with it from the get go. Predators of all stripes will come out to feed and whatever impractical "valuables" you might have won't last you long be that gold, diamonds or NFT art.