$BTC $BTC is the king of coins... if it falls all the coin fall n if it rise all coins follow it.. it is invented by an unknown person Satoshi nakamoto in 2008.. Use of Bitcoin as currency was started in 2009,, with the release of its open - source implimentation . it is the first decenterlised cryptocurrency based on a free market ideology . .it is mostly seen as an investment and has described by some scholars as an economic bubble . . Bitcoin a peer to peer electronic cash system . .