Pix is Brazil's instant payment system, launched by the Central Bank of Brazil in 2020 and quickly adopted for everyday transfers between people and businesses. Its name became shorthand online for sending money instantly, and the notification sound became a familiar cue in Brazilian social media, short videos, and memes about payments, debts, and payday. Creators reuse it because viewers recognise it immediately, even without on-screen text, and it still works as a quick, funny signal for money arriving in real time.