How many times do people need to hear it. It's not a fucking ponzi. I haven't bought a cent worth of BTC but I frequently trade them for tangible commodities, fiat currency and save them in encrypted wallets. It's called mining.
Yes and who bought your BTC? Why can't you accept the fact that one day they may decide to sell it for a fiat currency just like you did?
Who is stopping them from selling it?
What happens to the BTC economy even if they sell it? Absolutely nothing. It's called liquidity.
The market would be dead if nobody was selling. It would be impossible for non-miners to acquire bitcoins.
No, it's not going to crash because people change it to USD, EUR or JPY.
Is gold crashing because it's sold in massive amounts every day for fiat currency?
Gold is just a shiny commodity with no real value except that given to it by the market and it's rarity/difficulty of obtaining.
Paper and bank money is even more worthless.
It isn't even backed up by rarity and there's tons printed every day out of nowhere. Just look at the joke of a currency called Zimbabwean dollar (of which 100 trillion dollars is not worth even close to 1 bitcoin) because absolutely nobody trusts it anymore
Paper money doesn't even have trust or security backing it up (can be faked and passed off relatively easy even by semi-professionals), people only use it because other people use it and believe it's worth tangible goods.