The term “HODL” originally came from a post made in 2013 on the cryptocurrency forum 'Bitcointalk' shortly after the price of Bitcoin fell drastically in the period of a single day. 

"HODL" is a misspelling of the word "hold", a common advocation of crypto-currency traders.

Hodl has become the rallying cry for bitcoin enthusiasts around the world as they faithfully hold their bitcoin despite the assets notoriously volatile nature.