Fiat money when introduced, it was backed by gold. That means the country will print only that amount of currency, the amount of gold they have. But as the time passed, no one cared about the Gold anymore and the currency was printed like anything. And that's why you see the inflation is rising like anything.

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Now there will be a time where the currency will collapse. If it's a USD, then whole world will collapse. If it's a countries currency then again you are doomed. That's happened with Iran Currency. It's currency collapsed against USD and thus the assets people had as per Iran's currency are almost 0 as per the world currency. So now as an individual how you will prepare against this type of currency collapse.
This is where the hard assets comes into picture. There was a huge talk about the rent vs buy but the real estate is one asset which everyone should have. Even though it's small, it's good to have in your portfolio. Even if it's not generating any revenue. It will give a sense of ownership.
Next is the metals like Gold and Silver. If the currency collapses, Gold and Silver will be the asset which will still have the real value. And if you have a sizable metal portfolio, you will be surely save your portfolio even the currency collapse. Now in Iran the currency has collapsed but if someone has Gold, the value if gold will still be the same as per the USD value. I know in Iran, no one can buy it but when you come out of the Iran, you can still survive using the Gold itself.
Next is to have some asset which is not controlled by the country Fiat and that is Bitcoin. It's truly a digital gold because you will get the correct value in USD even if your currency collapsed.
