@pooya87. Stable in value against what, however? Where would we get the basis for bitcoin's value?
It is hard because value itself is mostly measured in terms of fiat and if we measure it in terms of anything else (gold, a barrel of oil, bag of potato, ...) that too can be volatile. But I suppose the best way is to measure it in terms of a combination of goods and services instead of fiat.
For example we can say bitcoin value is stable if your cost of living is 1
BTC and remains that way regardless of what happens to the price ($1k to $10k to $100k to $1000k).
Agreed, it is very hard and very hard to use bitcoin as a store of value and a medium of exchange because of volatility. If you run a business, you can accept bitcoin, however, it would not be very good to hold them because of bitcoin's volatility against the currencies that are being used to pay for the business' expenses. If the argument is for the business owner to speculate on the price, that would be very head shaking if the arguers want the business owner to also become a speculator. It might bankrupt him.
In contrast to fiat, fiat is always stable because it is used as a legal tender and is always controlled by a centralized government, so fiat always remains stable at all times.
Why do you thing fiat has been always stable?
In the united states, people have to pay around 8% more for their living costs compared to last year. There are many countries even with much higher inflation rates.
Fiat has been never stable in value.
However, for the holder who has bought bitcoin when it was more than $50k, the reduction in his wallet's value has reduced by more than 50%. What if he presently needs the money because of an emergency?