You should really look into http://losthorizons.com, and the book "Cracking the Code" both by Pete Hendrickson.

In a nutshell, the only people who owe taxes are those paid by the government. If you don't have a government job (or contract), then you're off the hook. Use form 4852 to correct the erroneous assertion by your employer that you made legislative "wages" or "income" (terms that differ from their dictionary definitions!).

Whether taxes apply to Bitcoin and other cryptos is thus immaterial -- if you didn't obtain the cryptos as payment from a government, then you never owe taxes on them, regardless of how their value changes against any other currency.