Currencies that are considered stable are not magically so - this is the result of a careful balancing act by central banks. Bitcoin doesn't have an equivalent entity managing the rate of increase in the money supply.
Welcome to investing. Adoption is success.
The "market cap" is currently over 16 billion dollars. It would place 68th when compared with 192 countries M1 money supply (2015) data: https://www.cia.gov/library/publications/the-world-factbook/...
The hash rate securing the network is currently at 2.5 quintillion operations per second which is really 5 quintillion SHA256 operations every second: http://bitcoin.sipa.be/ Speaking of pennies... if every operation was a penny laid flat on earth, you could cover the surface of the earth, land and sea, twice over every second.
Bitcoin surpassed the penny stock phase a long time ago.
Bitcoin's dirty little secret: Illegal drugs/services.