During the December 2013 crash, a Bitcointalk user titled a defiant, typo-riddled post "I AM HODLING." The community adopted the misspelling permanently; it is sometimes backronymed as "Hold On for Dear Life."
Beneath the meme is a serious thesis: bitcoin’s volatility is the price of its upside, most people fail at timing markets, and long holding periods have historically rewarded patience. HODLers treat drawdowns as noise, not signal.