FOMO = Fear Of Missing Out
HODL = Hold (To stay invested in bitcoin and not to capitulate in the face of plunging prices)
some more crypto slang...
ATH = All time high
BEAR = a trader who believes prices will fall
WHALE = a trader with a fat account, usually one who is bullish on the price of bitcoin
BAGHOLDER or BAGHODLER = An investor who has been hodling for too long, and is left to face the consequences
TO THE MOON = a cry for bitcoin’s price to rise sky-high
GOXED = Being fooled. Derived from the closure of the MtGox in June 2011
ADDY = Bitcoin or other crypto-currency public key (address)
(taken from misc sources over the net)