Verge was not pre-mined, that means even developers had to mine their coins, just like other users. The currency is limited to 165 billion coins. It is one of the few cryptocurrencies that support five different hash functions (namely Scrypt, X17, Lyra2rev2, myr-groestl and blake2s) giving its platform a higher level of security. It also means people can use different types of tools to mine for the coins. Since the coin mining is limited to a billion per year, XVG to USD rate will not experience any big fluctuations.