Just realized I was off by a decimal place: 9,223,372 trillion (int64) and unlimited. But not sure if there is a cap somewhere before that.
So why was worth so much in September?
Speculation like always I guess (That is about when it was first hitting exchanges). Might have been worth more back then due to the stake bug not being as evident and numbers being smaller (2k was large, kinda like 900 billion is now). Biggest surge was actually a few weeks ago i think.