I applied through an employee referral. The process took 4 weeks. I interviewed at WorldQuant (Beijing, Beijing) in Nov 2016
Interview
1. Take an onsite paper test consisting of 40 multiple choices(including basic math, probability and algorithm questions) within 90 minutes.
2. Six rounds of technical interviews.
3. One behavioural interview with hiring manager.
4. One interview with compliance officer.
Interview questions [10]
Question 1
A, B and C are time series and the following rhos represent their correlation coefficients.
rho(A,B)=0.7, rho(B,C)=0.8, what is rho(A,C)?
Why the correlation matrix is positive semi-definite?
Given a time series, e.g. stock price, try to find an algorithm to find the subsequence that maximizes {last element - first element} of time O(n)
What if we can at most hold the stock for k days?
There are N(sufficiently large) numbers that may repeat and x repeats more than N/2 times. Try to find an algorithm with time O(N) and space O(1) to find x.
Let's play a game: There are 3 white balls and 4 black balls in a black box. If you get a white ball out your payoff +1, and -1 with a black ball. You can stop anytime and repeat the game infinite times. Will you play the game?
Let's play another game: There are 100 balls, you and I pick the balls in turn, for each round you can pick 2^k balls(k=0,1,2,...). Do you have a strategy to win?
Given the daily return for past year(approximately 250 trading days) of the 500 componential stocks from S&P 500, we have 500*499/2 = 124750 correlation coefficients, What is the distribution of these coefficients?
1. Is it symmetric?
2. Is it shifting to the right or changing its shape?
3. Does it have a fatter tail than Gaussian? Why?
4. How to estimate the correlations?
5. Give me an estimate of the expectation of the correlations.
You have a large jar containing 999 fair pennies and one two-headed penny. Suppose you pick one coin out of the jar and flip it 10 times and get all heads, What is the probability that the coin you chose is the two-headed one?
Suppose we have a polynomial f(x) with real coefficients {a0,a1,...,an}of degree n unknown, we could input x and get the output f(x).
1. What is the minimum trials of input to get all coefficients?
2. What if all coefficients are integers?
3. What is all coefficients are positive integers?
Consider a bubble sort algorithm dealing with 1~100. What is the probability that after the first round of bubble, the 10th element is in the 20th address?
A,B and C choose a integer between 1 and 100 in turn to minimize the difference between the integer they choose and an unknown uniformly distributed random integer. B knows what A chooses and C knows what A,B choose. What is A's optimal strategy?
I applied online. The process took 2 months. I interviewed at WorldQuant in Nov 2025
Interview
Screening -> Online tests in math (many problems on a variety of topics) and programming (3 easy problems on data parsing and filling in gaps) -> 3 technical interviews (math, programming, and DS/finance), usually a few simple warm-up questions and 2 more difficult problems to test the depth of knowledge -> interviews with teams, talk about your experience, scientific work, then questions related to the specifics of the team you are applying for, you need to come up with hypotheses about the data -> rejection
Interview questions [1]
Question 1
The team interview included questions from the Green Book. The questions from other stages were unique but fairly straightforward, with the exception of one that asked about knowledge of mathematical induction.
I applied online. The process took 2 months. I interviewed at WorldQuant (Ho Chi Minh City)
Interview
There were 5 rounds in total. It began with a 30-question math assessment on HackerRank, followed by two face-to-face interviews focused on probability. Next, I completed a 24-hour take-home test and presented my findings. The process concluded with a final interview with a manager to assess cultural fit.
Very hard interview, I suggest you to study hard linear algebra statistics probability and more more more more because again it is hard very hard and I need to hit word qouata here
