Teen bitcoin millionaire Erik Finman says this is how much you need to invest to get rich

An American 19-year-old who made NZ$4.6 million from a $1300 investment says anyone can do it.

Erik Finman used the $1300 he received from his grandmother when he was 12 to buy bitcoins. He now owns 401 coins, worth $4.6 million, and says getting rich was easy.

"If you are smart about cryptocurrency over the next 10 years, many people can build their fortunes even better than before," he said in an interview with Business Insider.

"I say if you do not become a millionaire in the next 10 years, then it's your own fault."

Mr Finman said while bitcoin was what made him his fortune, other cryptocurrencies may soon overtake it. He pointed to the high cost of transactions and environmental impact of mining the coins as reasons why.

"Bitcoin has been around for a long time, and Myspace or Netscape have been successful for a while. But at some point, better products came on the market - Facebook or Google Chrome, as an example.

"Fact is, bitcoin as we know it today will not last forever. The only question is what comes next - either an update that solves the problem, or another coin will prevail."

He says if people are smart about what cryptocurrencies they invest in, they can build a fortune similar to his.

"New business models and innovations are still emerging in this area, and therefore, there are many investment opportunities. It's a new kind of gold fever, or a new kind of Silicon Valley - there are really plenty of opportunities."

Bitcoin's value rose 20-fold in 2017 but has since lost more than half its peak value, currently sitting at $11,640.

Many in the financial world have warned that the coin shows all the signs of being a bubble, and will one day pop.