Though data isn’t entirely final, early reports indicate that Super Smash Bros. Ultimate may have sold somewhere around 1.3 million copies in its first week in Japan. The information appears to come from Morgan Stanley based on Famitsu-recorded numbers.

We should have final data by Wednesday. If Famitsu’s early number holds up, it would be the largest opening ever for a Nintendo published game in Japan outside of the Pokemon series. Additionally, it would be the best debut for a Smash Bros. game yet.

Here’s a look at previous launch sales for the Smash Bros. entries:

3DS Super Smash Bros. for Nintendo 3DS 987.239 2.703.101 Nintendo 13/09/2014
WII Super Smash Bros. Brawl 816.198 2.315.401 Nintendo 31/01/2008
N64 Super Smash Bros. 183.097 1.632.046 Nintendo 21/01/1999
NGC Super Smash Bros. Melee 357.101 1.349.418 Nintendo 21/11/2001
WIU Super Smash Bros. for Wii U 244.747 789.947 Nintendo 06/12/2014

Source

https://nintendoeverything.com/super-smash-bros-ultimate-estimated-to-have-debuted-with-1-3-million-copies-sold-in-japan/

More than Smash 3DS and Wii U COMBINED  first week in Japan.

It also did almost double Splatoon 2's first week sales in Japan.

What a sales monster!! First week WW numbers will be huge

Waiting on official numbers (and MC) but i wonder if this number includes the bundle?

Itll be 2mil ship+difital fw in japan with 1.5mil-1.7mil as sell thru

Could it be 5 million global first week??

Did Famitsu count the Pokemon Let's Go digital bundle I wonder? I don't remember a big difference between Let's Go Famitsu and Media Creates sales but I'm not sure.

Probably not, blame Europe. 

If Nintendo had a global initial shipment of 5 million+ I don't see why not.

Definitely, I expecting we will have PR from Nintendo tomorrow, 5m+ is almost certain.

Thats the floor right now

They had it roughly the same #. So we could be looking at something much much greater here lol