Silver isn't undervalued. It only undervalued when you compare it to gold which is ludicrously over-valued right now.
Also, bullion makes a horrible investment. You get taxed up the ass for any gains you make. There is no such thing as long term capital gains for bullion. You'll get taxed at 28% fed tax in the US plus whatever your state charges. Where I live that is another 12%. So you would pay nearly 40% on something that is expected to just keep up with inflation over the long term. No thanks.
Bitcoin is riskier but is a better investment overall.
erm what are you talking about? no one knows what silver i have or dont have and there is no reason to expect anyone to know at any point in the future other than the person i sell it to someday. how on earth is the government going to tax me on that?