PRACTICE GUIDE JUMP TRADING
Jump Trading Quant Developer Practice Test
Jump Trading does not publish the shape of its quant developer screen, and candidates describe it as 2 to 4 problems questions in 60 to 120 minutes, roughly 20 to 40 minutes per question, written in a code editor and run against tests you cannot see.
Those are ranges across firms running this format rather than Jump Trading's own figures, so treat them as the shape to train against and check the instruction screen on the day for the marking rule.
Outcry is not affiliated with Jump Trading 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 Jump Trading’s own.
What it screens
A quantitative trading firm known for low-latency infrastructure and research across futures, equities and crypto.
- ✓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 Jump Trading
A quantitative trading firm known for low-latency infrastructure and research across futures, equities and crypto. What that means for the screen is that the questions tend to be drawn from the work rather than from a textbook, so the format below is the shape to train against rather than a syllabus.
Candidates also report 2 other screens at Jump Trading, covered separately on this site. Where a firm runs several, they usually sit in one round rather than spread across the process, so the pacing of the whole set matters more than any single section.
The format
Jump Trading does not publish this screen's shape, and it varies between firms, so these are the ranges candidates report rather than exact figures.
| Questions | 2 to 4 problems |
|---|---|
| Time | 60 to 120 minutes |
| Per question | 20 to 40 minutes |
| Negative marking | No |
| Answer style | Code editor, run against hidden tests |
| Where it sits | First technical round, usually on HackerRank or CoderPad |
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 Jump Trading’s.
Data structure implementation
Build the thing rather than call it: an order book, a cache, a ring buffer. Graded by hidden tests, so there is no partial credit for an approach.
Reading someone else's code
A diff or a function with a bug in it, and the question is where.
Example
You need the running median of a live price stream. Which approach is best?
- Two heaps - a max-heap of the low half and a min-heap of the high half
- Sort the buffer on every tick
- A single min-heap
- A hash map of counts
Answer Two heaps - a max-heap of the low half and a min-heap of the high half
Balanced heaps give O(log n) insert and O(1) median. Re-sorting is O(n log n) per tick.
Language and systems detail
Memory, references, undefined behaviour and the things that bite in production.
Example
A table holds 229,000 rows of 256 bytes each. Blocks are 4,096 bytes and rows do not span blocks. How many blocks does a full scan read?
- 14,313
- 229,000
- 218,000
- 16
Answer 14,313
4,096 / 256 = 16 rows a block once the remainder is discarded, since a row cannot straddle a block. 229,000 / 16 rounds up to 14,313 blocks. Dividing total bytes by block size gives 14,313 and quietly assumes no wasted tail.
Numerical and data handling
Floating point, aggregation and joins on data that does not fit the obvious shape.
Example
X and Y are independent, with standard deviations 17 and 30. What is the correlation between X and X + Y?
Answer 0.49301257198088033
Cov(X, X+Y) = Var(X) = 289, because X and Y are independent. SD(X+Y) = sqrt(289 + 900) = 34.482. So the correlation is 289 / (17 x 34.482) = 0.493. Adding independent noise to a series never makes the correlation zero, only smaller.
Edge cases
Empty input, one element, duplicates and overflow. The hidden tests always include them.
Probability behind the problem
Screens that look like coding questions and are really expectation questions.
Example
A strategy returns 19.8% a year with an annual volatility of 27.8%. Cash pays 3.7%. What is its Sharpe ratio?
Answer 0.579
Sharpe is excess return per unit of risk: (19.8% - 3.7%) / 27.8% = 16.1% / 27.8% = 0.579. The risk-free rate has to come out of the numerator, because holding cash earns 3.7% at zero volatility and no strategy should get credit for that. Using the raw 19.8% gives 0.712, which flatters the strategy by 0.133 and flatters it more the higher rates go.
What a good score looks like
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.
- 02Write the edge cases into your own tests first. That is where the hidden ones live.
- 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 Jump Trading
Common questions
- Is the Jump Trading quant developer test multiple choice?
- Reported as code editor, run against hidden tests. Formats move, so treat this as the shape rather than a guarantee.
- How long is the Jump Trading quant developer test?
- Candidates report 2 to 4 problems questions in 60 to 120 minutes, roughly 20 to 40 minutes per question.
- Is there negative marking on the Jump Trading quant developer 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.
Hiring now: current Jump Trading quant openings, refreshed daily.