$BTC Based on the ideology of the free market, Bitcoin was invented in 2008 by an unknown person known as Satoshi Nakamoto. Bitcoin began to be used as a currency in 2009 when its application was released as an open-source program. In 2021, it was adopted by El Salvador as legal tender. It is often viewed as an investment and has been described by many scholars as an economic bubble. Since Bitcoin is used under pseudonyms, it has been utilized by criminals, leading to regulatory attention and resulting in its ban in many countries as of 2021.