It depends.

Buying & selling, it's just like any other investment.

"Mining," on the other hand, probably belongs on a Sch C.

The way I think about it, if your money made (or lost) money, that's an investment.  If your time made money, that's earned income.  Next we can debate whether or not the activity rises to the level of a "trade or business" but I'd say mining probably belongs on a Sch C in most cases, subject to SE tax.

Rick

Forsage partners own smart contracts and by referral , partners earn Ethereum virtual currency. This would be a Schedule C, as it is actively running business, therefore, all their commission paid in ETH is taxable and subject to self employment income.  A partner can use those ETH commission to buy more contract in order to have more commission opportunities. 

I think there is 2 part to this, the commission earned as taxable income, and later on when ETH is converted to dollar, will result in capital gains depending on basis and market value. 

Is my understanding correct? If one individual owns 100 000 worth of ETH, US resident, do they need to file FBAR?

db provided more info here

Forsage partners own smart contracts and by referr... - Intuit Accountants Community

Mining is definitely schedule C, it is stated on IRS letter Notice 2014-21.

This Forsage is sort of mining for virtual currency, but it is done through smart contracts. There is definitely material participation involved. It is a business with intention to profit. The income is 2 parts, earned income when it is earned subject to SE tax, and capital gains when the asset is set to appreciate in value/or capital loss if it depreciates. 

@dbtaxsolutions If you have any new info to add, do it in your other thread.

Although I think it has been beaten to death.