It is ridiculous to compare Banro to Anglogold Ashanti.
There is no company called Ashanti anymore. Ashanti was bought by Anglogold when its hedge book blew up and it is now called Anglogold Ashanti. The Ashanti mine is only a piece of what is the 3rd or 4th largest gold producer in the world and whose mines are in South Africa, Mali, Ghana, Tanzania, DRC, Australia, etc.
Also a mining company's gold reserves in the ground are not valued at the spot price of gold, so they are not worth $13 billion. Not even close.