QQQ is the same as Nasdaq, for this meaning of Nasdaq.

The article isn't a great source, agreed. But it does give this calculation:

> Oddly enough, had SpaceX entered the Nasdaq-100 with a market capitalization of $1.75 trillion on Friday, March 27 [assuming the new rules (?)], it would have supplanted Tesla as the fifth-largest holding in the benchmark. The electric vehicle stock accounts for 3.8% of the Invesco ETFs.

So it would come in somewhere above 3.8%, by those calculations. And it depends on market prices from day to day. Not much changes about the argument above if you make it 3% or 6%, holding constant the assumption that it's 30% overvalued.