The 12th of February 2017 numerai gave 1M NMR to 12K users. NMR is based on ERC-20 (ethereum protocol). I was one of the lucky receivers. A few months later, crypto exchanges started trading with NMR and I sold my share.
In my country, the authorities started taxing cryptos with retrospective effect.
There is one way I can avoid paying tax: If the crypto was worthless or untradeable at the time I received it.
Question: Was it (theoretically) possible for me to trade the NMR at the time I received them (12th of February 2017)?