Pump group — a Telegram/Discord chat whose organisers announce a coordinated buy of a chosen low-liquidity token at a set time. The price spikes, outsiders FOMO in, organisers (who bought earlier) dump on everyone — including the group's own members, who are the real exit liquidity.
Participating is not "getting alpha", it is volunteering to be the bagholder in a pump-and-dump. On TON, low-cap Jettons are a favourite target.