Officially, we don't know what is at the end of the #UltimateCountdown.
Unofficially, it's pretty clear they have plans to reveal GeForce RTX 3000 series.
Nvidia started everyday posts on Twitter with #UltimateCountdown tag and our guess is that something is happening by the end of this week.
Is it a live stream? Or youtubers fill our subscribers feed with new RTX cards? We don't know.
https://twitter.com/NVIDIAGeForce/status/1292808003897311232