Bitcoin (₿) is a cryptocurrency invented in 2008 by an unknown person or group of people using the name Satoshi Nakamoto and started in 2009 when its implementation was released as open-source software.
The Black Vault went after FBI files on Bitcoin, and in November of 2020, the FBI released what they had. The case is still open, so additional records may be added in the future.
For now, what was released is below.
FBI File: Bitcoin [159 Pages, 7.3MB]