PRACTICE GUIDE FIVE RINGS
Five Rings Quant Trading Screen Practice
The Five Rings quant trading screen screen is 17 questions in 17 minutes - about 60 seconds 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: First online round. 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 Five Rings.
Outcry is not affiliated with Five Rings 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 Five Rings’s own.
What it screens
A proprietary trading firm in New York known for a heavily games- and puzzle-based interview style.
- ✓Expected value computed fast and used to make a decision
- ✓Conditional probability and Bayes updates without formal notation
- ✓Ranking likelihoods rather than computing them exactly
- ✓Fermi estimation: decomposing an impossible question into three easy ones
Where it sits at Five Rings
This is the whole sitting rather than one section of it: 17 items in 17 minutes, on one clock.
There is no going back. You answer or skip, and the next item loads, which means the decision to leave an item is final at the moment you make it.
The format
These are the numbers the Five Rings sitting on this site runs on, matching the format candidates report.
| Questions | 17 |
|---|---|
| Time | 17 minutes |
| Per question | 60 seconds |
| Negative marking | No |
| Answer style | Typed numeric answer, no calculator |
| Where it sits | First online round |
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 Five Rings’s.
Conditional probability
Bayes' rule in disguise: a test result, a signal, a drawn card, and what it implies.
Example
You have one fair six-sided die and need a uniform random number from 1 to 7. Which procedure works?
- Roll twice and take the larger, mod 7, plus 1
- Roll twice and take the sum mod 7, plus 1
- Roll once and multiply by 7/6, rounding
- Roll twice for 36 outcomes; re-roll on the last one, map the other 35 into 7 groups of 5
Answer Roll twice for 36 outcomes; re-roll on the last one, map the other 35 into 7 groups of 5
36 outcomes can't split into 7 equal groups, but 35 can (7×5). Discard one outcome and re-roll - the sum-mod-7 trick fails because sums are not uniform.
Distributions you should know cold
Binomial, geometric and uniform means and variances, applied rather than quoted.
Example
Two fair 6-sided dice are rolled out of sight. At least one shows a 6. What is the chance both do?
- 18.2%
- 2.8%
- 16.7%
- 9.1%
- 50%
Answer 9.1%
Outcomes with at least one 6 number 11, and exactly one of those has both, so 1/11 = 9.1%. The intuitive 1/6 answers the different question where a NAMED die shows a 6.
Estimation under uncertainty
A number nobody knows exactly, reasoned to the right order of magnitude out loud.
Example
Whole numbers are picked one at a time, and you get to keep picking. How many do you have to pick to be certain that two of them leave the same remainder when divided by 18?
Answer 19
The remainders are the 18 boxes, 0 through 17. Picking 18 numbers can dodge a repeat exactly once, by hitting every remainder, so 19 forces one. The same statement says two of the picks differ by a multiple of 18, which is how this argument usually turns up.
Waiting times and repeated trials
How long until the first success, and why the answer is rarely the average you expected.
Example
A quote engine throws an average of 1.9 errors an hour, Poisson. What is the chance of an error-free hour, as a percentage?
Answer 15
P(0) = e^−1.9 = e^−1 × e^−0.9 ≈ 0.3679 × 0.41 ≈ 0.1496, so about 15%.
Symmetry arguments
Questions that collapse to one line once you notice the two cases are mirror images.
Example
A fair 10-sided die pays its face value, plus a bonus of 6 if it lands on 10. What is the expected payout?
Answer 6.1
The face averages 5.5 and the bonus adds 6/10 = 0.6, giving 6.1.
Reading the question exactly
At least, exactly, and given that - the three phrases that change the answer entirely.
Example
A price rises 58% in one quarter and then falls 40% in the next. What is the net change over the two quarters?
- -5.2%
- 18%
- -23.2%
- -18%
Answer -5.2%
100 goes to 158, then loses 40% of 158, landing at 94.8. Net -5.2%. The naive answer 18% misses the cross term, which is -23.2%.
What a good score looks like
On a paper of 17 questions with no penalty for a wrong answer, the only thing an unanswered question can do is cost you. Probability rounds are usually marked as part of a wider battery, so a standalone threshold is rarely reported. Where candidates do describe one it clusters around getting two thirds of the items right, with the caveat that these sections are short enough that two mistakes move you a long way.
How to train for it
- 01Work the standard results until they are recall, not derivation: complement, conditional, binomial mean and variance, geometric expectation.
- 02Do them timed. A probability question you can solve in four minutes and the paper gives you ninety seconds for is a question you cannot solve.
- 03Sanity-check the magnitude before committing. A probability above one or an expectation outside the range of outcomes is a caught error, and these papers plant both as options.
TRAIN IT HERE
The drills that match each section
Likelihood Ranking
Order events from most to least likely - the exact screen-question format.
Fermi Estimation
Piano tuners in Chicago, atoms in a body - scored on order of magnitude.
Quitters Never Lose
A casino stopping-strategy game that is secretly a martingale lesson.
Tail Risk
Rare events and fat tails, and what they do to a plain expected-value estimate.
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 Five Rings
Common questions
- Is the Five Rings quant trading 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 Five Rings quant trading screen test?
- 17 questions in 17 minutes, which is about 60 seconds each.
- Is there negative marking on the Five Rings quant trading 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 Five Rings Quant Trading Screen sitting puts the sections back to back on one clock.