What is ATH?
ATH meaning and ATH definiton
ATH is an acronym used for All Time High and has very little to do with being high all (the) time. It happens when the price of an asset (in this case, a cryptocurrency) reaches it's peak level. If you bought it before the ATH you do actually feel a bit high.
You used to see it daily back in the end of 2017, and cryptocurrency holders were very excited in sharing their HODL memes with everyone. As the bearish market has set in, there's even an website to see how much time has passed since the leading cryptocurrencies reached their ATH.