PRACTICE GUIDE SQUAREPOINT
Squarepoint HackerRank Screen: what the test is, and how to train for it
The Squarepoint HackerRank Screen screen is 12 questions in 60 minutes - about 5 minutes each - answered by typing the number, with no calculator. There is no negative marking, so leaving an item blank gains you nothing over guessing.
Where it sits: HackerRank screen. The practice sitting on this page runs the same item count, the same clock and the same marking rule, with questions generated by Outcry rather than taken from Squarepoint Capital.
Outcry is not affiliated with Squarepoint Capital and has no access to their assessment content. This guide describes an assessment format that candidates report publicly; the questions here are generated by Outcry and are not Squarepoint Capital’s own.
What it screens
A global quantitative hedge fund based in New York and London, trading systematic strategies across asset classes.
- ✓Reading concurrent code and pointing at the defective line
- ✓Order-book data structures: what happens on a cross, a cancel, a partial fill
- ✓Algorithmic complexity chosen for the input sizes stated in the problem
- ✓Monte Carlo methods and when a simulation beats a closed form
Where it sits at Squarepoint Capital
This is the whole sitting rather than one section of it: 12 items in 60 minutes, on one clock.
You can return to earlier items within the section, so a first pass for the quick ones and a second for the rest is a workable plan.
The format
These are the numbers the Squarepoint sitting on this site runs on, matching the format candidates report.
| Questions | 12 |
|---|---|
| Time | 60 minutes |
| Per question | 5 minutes |
| Negative marking | No |
| Answer style | Typed numeric answer, no calculator |
| Where it sits | HackerRank screen |
What it tests, with a worked example
Every example below is generated by Outcry, drawn from the same question generators the timed drills run. None of them is Squarepoint Capital’s.
Complexity that is actually graded
Hidden tests sized so the naive solution times out. A correct answer that is too slow scores the same as a wrong one.
Reading someone else's code
A diff or a function with a bug in it, and the question is where.
Example
Position is accumulated in a double and the code tests `if (position == 0.0)` to detect flat. What goes wrong?
- Comparing doubles is undefined behaviour
- The compiler removes the comparison
- 0.0 and -0.0 compare unequal
- Accumulated rounding leaves a residue, so the test is false when the book is flat
Answer Accumulated rounding leaves a residue, so the test is false when the book is flat
Adding and subtracting fills in binary leaves a residue around 1e-15. Compare against a tolerance, or hold size in integer lots and never in a double.
Numerical and data handling
Floating point, aggregation and joins on data that does not fit the obvious shape.
Example
A price walks on the whole numbers 0 to N. Each step it moves +1 with probability p and -1 with probability 1 - p, independently. It stops the first time it touches 0 or N. N = 8 start = 4 p = 0.6 One question, six parts. Each part uses the part before it.
Part 3 of 6. Now use p = 0.6. What is the probability the walk stops at N?
Answer 0.8350515463917525
With drift the answer is (1 - r^start)/(1 - r^N) where r = (1-p)/p = 0.6667. That is (1 - 0.1975) / (1 - 0.039) = 0.8351. Part 1 gave 0.5, so the drift is worth 0.3351 here.
Edge cases
Empty input, one element, duplicates and overflow. The hidden tests always include them.
Statistics in code
Rolling windows, correlations and quantiles, implemented rather than imported.
Example
A population has standard deviation 8. What is the variance of the mean of 25 independent draws?
- 1600
- 64
- 2.56
- 0.32
Answer 2.56
Var(X̄) = σ²/n = 8²/25 = 64/25 = 2.56. The three wrong options are the population variance 64 left undivided, the standard deviation over n rather than the variance, and 1,600 - the variance multiplied by n instead of divided by it.
Reading a spec precisely
Return type, ordering and tie-breaking are graded, and are where most silent failures come from.
What a good score looks like
On a paper of 12 questions with no penalty for a wrong answer, the only thing an unanswered question can do is cost you. Coding screens are usually pass-fail on hidden tests rather than scored, and candidates commonly report that a solution passing every correctness test still fails on a timeout. Treat full marks as solving every problem inside the complexity bound, not merely solving it.
How to train for it
- 01Implement the core structures from scratch once each. The screens ask you to build them, not use them.
- 02State the complexity before you write. If it is worse than the input size allows, the approach is already wrong.
- 03Practise without an autocomplete. The screens run in a bare editor, and the gap between writing code with help and without it is larger than most people expect.
TRAIN IT HERE
The drills that match each section
Concurrency Clash
Find the data race, name the fix - real C++ defect patterns, five levels.
Order Book
Matching-engine mechanics: crosses, cancels and partial fills.
Algorithm Lab
DP tables, Monte Carlo estimation and speed rounds at four difficulty tiers.
SIT THE FULL BATTERY
All the sections back to back on one clock, marked the way the real screen marks them, with a by-skill breakdown at the end. Included with any pass.
Also reported at Squarepoint Capital
Common questions
- Is the Squarepoint HackerRank Screen test multiple choice?
- Typed numeric answer, no calculator. You type the number, so there is nothing to eliminate your way to.
- How long is the Squarepoint HackerRank Screen test?
- 12 questions in 60 minutes, which is about 5 minutes each.
- Is there negative marking on the Squarepoint HackerRank Screen test?
- No. A wrong answer costs nothing beyond the mark you would have earned, so leaving an item blank is never better than guessing at it.
- How do I practise for it free?
- Every drill linked on this page is free to play, with no account, inside a daily run cap. Questions are generated fresh each run, so there is nothing to memorise between attempts. The full Squarepoint HackerRank Screen sitting puts the sections back to back on one clock.