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Probability and Markets [pdf]

janestreet.com

61–70 of 75 posts

Re: Probability and Markets [pdf]

#61
post #58

Earlier quoted context omitted.

It shows JS doesn’t scan for morality or ethics or judgement.

Were you screened for morality or ethics at your current job?

I was. You were too. It's just called "culture fit" in polite society.

Re: Probability and Markets [pdf]

#64
post #44

Earlier quoted context omitted.

Why? Maybe they were good employees? Just because they did something bad after really isn't thst relevant.

It shows JS doesn’t scan for morality or ethics or judgement.

These are hard to scan for. Also people can change?

Re: Probability and Markets [pdf]

#65
post #53

This seems like a sub-optimal way of finding top talent, even though the results still speak for themselves. Obviously Jane Street has had a lot of success using brain teasers to screen for talent. If i were a hedge fund recruiter, here is what I would do: Go on /r/ wallstreetbets and find guys who consistently are pulling huge $ like this guy: https://old.reddit.com/r/wallstreetbets/comments/14a9xyi/11m... Send a DM…

Jane Street is a market maker. WSB is a gambling forum where people are addicted to chasing huge rewards by taking huge risks. This would be about as interesting as going to a casino and recruting people who have a big win streak at the slot machine.

but there is evidence that some traders there are more skilled than others, like the guy I linked to (or someone like Warren Buffett or Jim Simons ). it's not all random like a casino. Plus, to make so much money at options trading so consistently, requires knowledge of position sizing, market intuition, pattern recognition, and other skills relevant for all aspects of trading.

Re: Probability and Markets [pdf]

#66
post #44

Earlier quoted context omitted.

Why? Maybe they were good employees? Just because they did something bad after really isn't thst relevant.

It shows JS doesn’t scan for morality or ethics or judgement.

Plenty of tech nerds have turned into complete psychopaths when they pocketed their first billion.

Re: Probability and Markets [pdf]

#67
post #44

Earlier quoted context omitted.

Why? Maybe they were good employees? Just because they did something bad after really isn't thst relevant.

It shows JS doesn’t scan for morality or ethics or judgement.

Unless you happen to have some evidence presenting unethical and/or immoral actions on the part of SFB and Caroline during their tenures at JS, it only shows that JS don't try be an oracle predicting future morality or ethics or judgement of their candidates for the rest of their lives.

JS aren't future tellers when it comes to their employees' lives after they leave JS, and JS has no control over those employees once they depart either.

Re: Probability and Markets [pdf]

#68

During my university studies, I found it surprising that although some topics from advanced courses might be applicable in certain jobs like at Jane Street, interviews often emphasised the fundamentals and understanding of basic concepts such as basic probability theory, rather than some specialised knowledge in Lie processes. If you look through this PDF it does not even cover a 1.semester course in probability theo…

I heard they try to hire for aptitude/talent. The sophisticated stuff they will teach you if you’re hired. This is similar to how math Olympiad students are picked, most questions involve combinatorics and Euclidean geometry instead of advanced calculus, as anyone can understand a basic counting problem, but it’d take a few semesters to define the terms in a typical calculus problem.

Although Olympiad is only counting, there is considerable prep and practice that goes into it.

Re: Probability and Markets [pdf]

#69

Earlier quoted context omitted.

I heard they try to hire for aptitude/talent. The sophisticated stuff they will teach you if you’re hired. This is similar to how math Olympiad students are picked, most questions involve combinatorics and Euclidean geometry instead of advanced calculus, as anyone can understand a basic counting problem, but it’d take a few semesters to define the terms in a typical calculus problem.

Although Olympiad is only counting, there is considerable prep and practice that goes into it.

That’s true. I meant (almost) everyone can understand the ‘statement’ of Olympiad-level counting problems, but of course solving them is another issue.

Re: Probability and Markets [pdf]

#70
post #37

Earlier quoted context omitted.

The very idea underlying statistics (that we can learn something useful from a class of events by ignoring specifically that which makes them different from each other) is a very recent invention -- only a few hundred years old -- and it's still counter-intuitive to a lot of people. Ask people to predict whether the Jones' have a dog and they'll start asking questions about the specifics of the Jones', like do they h…

> Ask people to predict whether the Jones' have a dog and they'll start asking questions about the specifics of the Jones', like do they have children, do they live in the suburbs, have they always wanted a dog, etc. Then they try to construct a narrative based on "logical" conclusions. This is the core idea of Bayesian statistics. You fall back to the background rate only if you have no ability to access more pertin…

When people ask about whether the Jones' have children, they do not (most of the time) have an accurate conditional probability of dog ownership given a certain number of children. They are trying to construct a story that seems plausible.

The difference between Bayesian reasoning and narrative fallacy is a coherent evaluation of joint probabilities -- the bit most people skip over.

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