I invested in cryptocurrency, but the company I invested in (yuan-currency.com) disappeared and I lost all my crypto. How to report it?

You will have to enter as an investment like worthless stock--to report your your loss.  You can report it in the year they are deemed to be completely worthless. This usually happens when a company stops doing business or files bankruptcy.  You should be prepared with your proof and retain it in your tax file.

The sales price would be zero and the cost basis would be what you actually paid for the stock and December 31st as the date of sale.  You should use the description as 'Worthless'.

To enter worthless stock as investment sales:

1. Open (continue) your return in TurboTax. 
2. In the search box, search for investment sales then click the "Jump to" link in the search results.
3. Answer Yes to the question Did you sell any investments?
4. If you land on the Here's the investment sales we have so far screen, click Add More Sales.
5. Answer No to the 1099-B question.
6. On the next screen, select Other.
7. Continue following the onscreen instructions to enter the sale.