Bitcoin is NOT a currency. It is a thing. Like a piece of wood that people are bartering for goods and services. There is no inherent value in it and it is subject to the greater fool theory.
Now blockchain technology is a GREAT invention. And, will be incorporated into all kinds of things that we use everyday. From currency transactions to voting and even real property transfers.
I could use cryptocurrency to buy goods and services. But I would NEVER buy and hold any cryptocurrency for any longterm. There is no history to it's value and we will find out where the floor is on the price.
My nephew told me that he wants to buy and hold cryptocurrency for his retirement plan....LOL...I hope he didn't.
Good luck !
And what is the history behind the US dollar? Why are you so confident to hold 100% in US currency? Or Gold? The US dollar is fiat currency, which still makes it a real currency. There is no INTRINSIC value behind gold either, and yet people still hold it as assets.
And by the way, bitcoin is not a thing like a "piece of wood," because wood actually does have INTRINSIC value as building material and fuel.
All retirement plans are risky. All holdings are risky. Some are riskier than others, and bitcoin is clearly riskier, at this point in time, than other holding options. The safest being bonds and CDs, the riskiest being stocks, and somewhere in between is fiat cash and bullion. All of it is at risk, and this is why it is so important to have smart people running the government and keeping watch over the rats and snakes that want to take total control of the entire economy and global market.
At least your nephew is trying to actually have a retirement plan.