I mistakenly didn't report virtual currency transactions on my original return. I had very few virtual currency transactions in 2020, resulting in a minor short-term loss of a few dollars (no change to federal refund or amount owed). I added the transactions to the Cryptocurrency income section, but the preview of the amended 1040 still shows "No" as an answer to “At any time during 2020, did you receive, sell, send, exchange, or otherwise acquire any financial interest in any virtual currency?”. The preview of the amended return does show the Cryptocurrency transactions.
