How did he lose the money? Did he sell the bitcoin? Stop the bs.
Unless you expect Bitcoin to return to this valuation, the money is as good as lost.
So you could say his investing skills measured in either bitcoin or dollars are poor to date.
The reason it is "unrealised" until that point, is that you could instead simply hold until/if the price of Bitcoin (priced in fiat) rises past the level you bought it at, and still sell at a profit (in real terms if you account for inflation, or in nominal terms if you don't).
Then that would be a realised profit.
Hence the distinction between unrealised and realised.