Rapper 50 Cent made millions from bitcoin without realizing it as he let people purchase his album "Animal Ambition" back in 2014 using the cryptocurrency, which cost only $662 at the time.

The popular rapper forgot about it and left his account unused for years, all the while earning some 700 bitcoin, or $400,000 in 2014, according to an initial report in TMZ.

The recent cryptocurrency surge, however, multiplied the rapper's gain from Animal Ambition as now his 700 bitcoin is worth more than $7.5 million, calculated according to bitcoin's Thursday value of roughly $11,000.

Confirming the news on Instagram, 50 Cent said: "Not bad for a kid from South Side, I'm so proud of me."

Bitcoin, a virtual currency created from computer codes, was worth only a few U.S. cents when launched in 2009 by someone using the Japanese-sounding name Satoshi Nakamoto.

Unlike a real-world unit such as the U.S. dollar or euro, bitcoin has no central bank and is not backed by any government.

The value of bitcoin, along with other cryptocurrencies, skyrocketed this year, reaching the record heights of a little over $20,000 before plummeting sharply to $10,000 in January as many holders began selling their savings.