Sure, those places are finicky and they ask tough questions. But can someone tell us where, exactly, this top .25% figure comes from? Other than the swirling

Sure, those places are finicky and they ask tough questions. But can someone tell us where, exactly, this top .25% figure comes from? Other than the swirling mass of air about their heads, as they typed it? I'm not asking this to be snarky. It's just that people keep talking about the "top .1%" as if it's not just a thing, but a quantifiable, measurable thing. It's neither, of course; basically it's just a hunch people have. With an arbitrary number slapped on it to make it sound more, you know... authoritative. Meanwhile, some stories of the top .25% at Jane Street, getting busy at the task of finding the other top .25%: My interview is scheduled at 10:00am. However, I wait until 10:15am but no one called. Then I received an email saying the interviewer was wrapping up with an issue and he would call around 10:30am. Then I wait until 10:45 am still no one called. I received another email saying he was still working on the issue and will call in a minute. Then I continue to wait to 11:15am.… Another: They ended up calling 40 minutes late, the interviewer was very incompetent at even asking the questions. I found it very unprofessional and chose to not move on in the interviewing process after speaking with friends who told me this was not uncharacteristic of them. Source: glasdoor.com