If it's Pokemon, it's possible. But if you're so skeptical, just wait for official numbers.

Pre-order tracking on VGChartz is a joke anyway. It's rarely a good indicator of first-week sales.

Because people made a thread about how Pokemon would outsell GTAV in 1 week. Some even said 1 day.

a lot of people said that PS4 will outsell Wii U LT day 01... so what is your point?

Anybody with a brain knows thats impossible, and besides only 2 or maybe 3 people thought it would (which they are indeed delusional). Anyway we dont have official numbers yet but if it is over 5mil in just one day this pokemon game will indeed do very very very well. 

The doubters in this thread:

It could if it wasn't sold out everywhere.

but its not, your prediction of pokemon declining is dead wrong as well

well...you clearly haven't read that thread. A ton of people in that thread beleived that XY will outsell GTA V LT.

PS: It's less than half of GTA V's day 1

Maybe you guys should take this conversation into that other thread, then. As it stands, this seems to have little to do with the question of whether it's possible for XY to have sold 5.5 million first week.

Don't be hasty. Sales can be very front-loaded. I also wouldn't be surprised if vgchartz is wrong here. Let's wait for a few more weeks.