Earlier quoted context omitted.
One other note on Tesla in particular, that I think the other comments here have largely missed: Tesla is--and has been for a while now--the largest market cap company that is not included in the S&P 500. To be considered for inclusion in the S&P, companies must show at least 4 consecutive quarters of profitability. Tesla's next earnings release (which is in roughly two weeks) has the possibility of being that fourth…
> stocks normally join in the 500s - 300s or so, and grow from there. Does 500 - 300 represent the share price? If so, do most companies issue a similar number of shares before getting included in the S&P?
In most cases a company lifecycle is like, we launched a company, it's private for a few years, then it goes public. Either shortly before going public, but maybe a few years after, it becomes profitable. It then grows and grows etc, and joins the S&P by virtue of its size getting larger than the 500th-ranked firm already in the S&P ("size" here is market cap).
Tesla is different, because Tesla went public and was unprofitable, then got ~big and was still unprofitable, and now for (largely unknown) reasons would be, if it were included, the 10th largest company in the S&P, but is still unprofitable. They may cross that threshold later this month, but this process--joining the S&P at rank 10--is highly unusual.