Originally Posted by Roentgen

If you mean #1 in global rankings, I don't think there has been a way to find out within the game.

What I'm aware of is he's on Discord, should be somewhere in the 510k range by now.

Hm... while I'm tops on a number of lists here, I doubt I'm even top 100 global. IIRC I'm like 453k right now, been stuck at 15 rainbows since, you know, there's been a serious lack of guaranteed rainbow deals lately (barring current)