Earlier quoted context omitted.
> and the thousands under them are getting salaries. The difference is that these thousands also get to invest in Jane Street, which seems a pretty profitable investment (70% margins, etc).
Typically at such companies you have to be at the very top of the hierarchy to be able to buy in and get a slice of the profits. It is very unlikely that rank and file employees are able to participate, at least at a scale larger than, say, a Google employee buying some extra shares.
>20% return is quite easy to justify. You're also looking at a 50%-200% annual bonus, mostly leaning to the higher end of the range.
Its a very different world!