is silvers market cap only at 15 Billion USD?
Closer to $22B1 tonne silver is about US$725K
There are about 30K tonnes in reserves
(and over 1M available to be put in reserves so real number is closer to $800B)
Maybe he is just considering american eagles.
And only considering one aspect of Bitcoin.
Total world reserve is 540K tons which equals about 450bn market cap.
http://minerals.usgs.gov/minerals/pubs/commodity/silver/mcs-2013-silve.pdf