Jane Street

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Jane Street Assistant Trader Interview Questions

Updated Jan 26, 2015
Updated Jan 26, 2015
136 Interview Reviews

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Assistant Trader Interview

Anonymous Interview Candidate
Anonymous Interview Candidate
Application Details

I applied online – interviewed at Jane Street.

Interview Details

The interview was over the phone for about 45 minutes. I was asked three questions that had to with probability and the questions seemed a little unusual. They called a couple of minutes late and were good about it if i had to reschedule. they also allowed me to use paper and pencil.

Interview Questions
  • You have two dices. There are two players. You each pick a number. The person who picks the number closest or equal to the sum of the roll of the dices is the winner. What is the strategy to optimize chances of winning.
    Also, is it always better to pick the number that has the highest chance of being rolled? This situation does not apply to the rules of this game. For example, this question could apply to the rules when the two numbers on the die are multiplied rather than added.
     
    View Answer
No Offer
Difficult Interview

Other Interview Reviews for Jane Street

  1.  

    Assistant Trader Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Application Details

    I applied online. The process took 2 weeksinterviewed at Jane Street.

    Interview Details

    I submit and resume online and was contacted a few weeks later for an online-test. One day after the online test, I was emailed to schedule a second-round interview.

    The phone interview was with a trader who was super nice. He was helping me out when I stuck at solving the problems.

    Interview Questions
    • online test - conditional probability.
      phone interview - general probability questions, but more difficult.
       
      Answer Question
    No Offer
    Neutral Experience
    Difficult Interview
  2.  

    Assistant Trader Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Application Details

    I applied online – interviewed at Jane Street.

    Interview Details

    Contacted about the assistant trader position, and set up a phone call. A couple math and probability questions, not too difficult now that I think about it, but definitely hard to do on the spot. Did not move on to the next step in the interview process. Probably a good idea to brush up on mental math and tricks to simplify problems.

    Interview Questions
    No Offer
    Difficult Interview
  3.  

    Assistant Trader Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Interview Details

    Got an on campus interview. Lots of probability questions, and mental math. Typical thing that you would expect for a trader. The dressing code is super casual as the culture of the company suggests. I would recommend you to be prepared for lot's of mental math and brain teasers before you go to an interview for Jane Street

    Interview Questions
    • If you would ask all Americans a yes or no question, what would you ask to get the most of them wrong   View Answer
    No Offer
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  5.  

    Assistant Trader Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Application Details

    I applied online. The process took 4+ weeksinterviewed at Jane Street in November 2014.

    Interview Details

    Applied Online. Had 3 phone interviews. The first interview consisted of a bunch of easier questions involving probability/statistics. The second interview had 3 questions and required confidence intervals. The third interview was personal questions and one question on blind bidding for 100 dollars. The personal questions are very important as I didn't mess up any math questions yet I didn't receive an offer.

    Interview Questions
    • Give a 90% confidence interval for the weight of Mount Kilimanjaro   Answer Question
    No Offer
    Neutral Experience
    Average Interview
  6. 4 people found this helpful  

    Assistant Trader Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Interview Details

    This was for second round (phone interview), after a first round with a recruiter on campus. They emailed me 20-30 minutes after my scheduled interview time to say they were unavailable. Arranged to have interview later that day. Lots of probability questions (in both rounds).

    Interview Questions
    • How many commercial airplanes are bought in the U.S. every year? Give 90% confidence.   Answer Question
    No Offer
    Difficult Interview
  7.  

    Assistant Trader Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Interview Details

    It was a similar process to what others have already described. You have to be ready for the types of questions they will be asking, otherwise you should probably wait on that interview. It's not very hard to get the initial interview, but keep in mind that you'll go through progressively harder interviews.

    Interview Questions
    • Similar to what others have stated, make sure you know basic probability, combinatorics, and can do these in your head.   Answer Question
    No Offer
  8.  

    Assistant Trader Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Application Details

    I applied online. The process took 2 weeksinterviewed at Jane Street.

    Interview Details

    telephone interviews just brain teasers. Missed a trick on the first interview but they still wanted to schedule a second one so it's mostly about the reasoning.

    Interview Questions
    • person A has a 30 sided and person B has a 20 sided die. both players role and the person with the highest role win (on a draw B wins). the loser pays the winner the value of the winners die.
      1. calculate expected value of this game for player A (easy)
      2. how does this value change if player B can re-roll and when should he re-roll.
      3. now how much is it worth for player A to get a re-roll option in this scenario.
      4. remove player A reroll. how many re-rolls do player B need in order for him to be a favorite in the game.

      i believed i solved 4 and 2 I had a decent idea but 3 is very difficult since optimal strategy might change based on opposing players optimal strategy.
       
      View Answers (8)
    No Offer
    Difficult Interview
  9.  

    Assistant Trader Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Interview Details

    They were pretty slow in their follow up after interviews, I had to email them every time before they'd remember to send me to the next round. The interviews were interesting and technical. Be prepared to answer questions quickly, without pen and paper, in the first round at least. Later on the questions get harder but they allow you to use writing materials.

    Interview Questions
    • I did initially misunderstand this question and had to be helped along, but it is fairly difficult to do on the fly anyway: "We're playing a game with an unbiased 30-sided die. Before we roll, we both pick (distinct) numbers between 1 and 30, and then we roll the die. If the number that appears is closer to the number I picked, you pay me, in dollars, the number on the die; if it is closer to the number you picked, I pay you, in dollars, the number on the die; if it is equidistant we do nothing. What's the optimal strategy - do you go first or second, and how do you pick your number? What's your expectation?"   View Answers (3)
    No Offer
  10.  

    Assistant Trader Interview

    Anonymous Interview Candidate
    Anonymous Interview Candidate
    Application Details

    I applied through college or university – interviewed at Jane Street.

    Interview Details

    On campus review

    Interview Questions
    • If you could ask one true or false question to all Americans and wanted to minimize the number of people who got it right, what would you ask?   View Answers (3)
    No Offer
    Average Interview

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