If your BTC are in a personal wallet, and a hard fork/airdrop occurs.. If you are unaware of it, and never download the new wallet... It will prolly come down to how understanding the IRS auditor is.. either you owe it, cuz you *could* get control if you downloaded the new wallet, or you don't owe, cuz you obviously wouldn't download a wallet for something you were completely unaware of...
I think this makes sense. What if there was some Bitcoin Gold, Bitcoin Green, Bitcoin Purple, Bitcoin Silver, Bitcoin Platinum, Bitcoin Diamond, Bitcoin Whatever ...
And you never downloaded the wallet, so the fork coins actually never moved ... when they do decide to tax you, the value of the coins at today's rates should apply, otherwise you can just say, I'll pay you in the forked coins ... What is your Bitcoin Whatever address, I'll send the tax owed on it.
That would make more sense.
But then, I don't know if the IRS will interpret it that way.
They can't tax you what it was worth yesterday, when you are paying them today. As any gains or losses were unrealized.
Sure they can and they will. It doesn't matter if you sell them. When you sell them, that's a separate taxable event which would probably be a loss if the value dropped since the coin was created.
If you had access to those coins and were aware of those coins, that is 100% taxable based on the value when they were created or when you had access to them, whether you accessed them or not.
In an audit, it would be hard to argue you didn't know about it or didn't have access to the coins, if they can show you as a prominent member of the bitcoin community and you had the expertise to access the coins.
Selling them today or paying the IRS has nothing to do with the gain realized when the coins were created. If you do sell them at a later date, that is another taxable event.