That's fine. Considering the business Jane Street engages in is highly competitive (maybe even the most competitive in the world), if their hiring practices cause them to have lower productivity, the market will force them to correct their practices or go out of business.
In fact, historical evidence shows amply that the more competitive an industry, the less discrimination (of the sort that we talk about now, like on racial or ethnic grounds) is to be found; and the most regulated, monopolistic, or anti-competitive the field, the more such discrimination is found.
In fact, historical evidence shows amply that the more competitive an industry, the less discrimination (of the sort that we talk about now, like on racial or ethnic grounds) is to be found; and the most regulated, monopolistic, or anti-competitive the field, the more such discrimination is found.