Thanks, yeah how about like 1 entire bitcoin? Lets say someone bought bitcoin every couple weeks over time and has 1 bitcoin. Bought via exchange, and ATMs that don't require ID and just converted to XMR, sent to another address and converted out to bitcoin. So there aren't many records.
And lets say the individual is not going to spend or sell the bitcoin until it reaches 1 million dollars... which could be in the far far future, 20 30 maybe 40 or 50 years from now. Something that makes it possible that records held by the ATM and exchanges could be gone if those exchanges go out of business.
And, if someone had 10 anonymous bitcoins.... I'm thinking they should wait till it goes up past 70k again and move to a more tax forgiving country, or a country that will not be afraid to tell the US to go F-off... And honestly there are few nations that will do that, maybe Russia? Although being prepared to follow all the laws of this new country you have moved to because you've burned your bridges.
What you are asking has been discussed in several threads, for example this one:
https://bitcointalk.org/index.php?topic=5355749.0The answer to your question depends a lot on where you live, but to summarize.
Showing up with a Bitcoin when it's worth $1M before tax authorites is the same as suddenly showing up with $1M in dollars that you can't justify.
In the best case scenario you will be chage a tax, which could be capital gains tax with 0 purchase cost in the case of Bitcoin and I am not so sure in the case of cash. It could be the same or it could be income tax.
But I am inclined to think that you would be investigated for tax evasion. Think Al Capone was put in jail for tax evasion: they couldn't prove that he murdered, extorted money, etc. The only thing they could prove was that he had more money than he could legally justify.
So, $1M seems to me a considerable amount of money to open such an investigation. If you have $1k in Bitcoin that you can't justify you're not going to have problems but when the amount gets big you risk ending up in jail.