Flow Traders · Online Assessment · Numerical + sequences screen

Flow Traders Sequences Test: Free Numerical and Sequence OA Replica

Candidates report that the Flow Traders online assessment for trading roles opens with a timed mental-math section of about 8 minutes that most people do not finish, followed by a separate number sequences section of about 25 minutes, both multiple choice and with wrong answers penalised. Sit both sections below in the same shape, get a penalty-adjusted score and a per-section breakdown. No signup.

40arithmetic, 8:00

30sequences, 25:00

+1 / −1right / wrong

0skipped

2sections, one sitting

Format reconstructed from candidate reports collected for our Flow Traders online assessment guide and the Optiver vs IMC vs Flow Traders comparison. Question counts are our estimate; see how this replica works.

What the Flow Traders numerical test actually is

Flow Traders is an ETF market maker, and its trading screen is built to find people who are fast and accurate with numbers before anyone looks at a CV. Candidates describe the Flow Traders OA as two separate timed modules. The first is a mental-arithmetic sprint in the spirit of Optiver's 80 in 8: short addition, subtraction, multiplication and division across integers, decimals and fractions, in both direct and missing-operand form, with far more questions than the clock allows. The second is a number sequences module closer to IMC's 24 in 18: find the next term, five options, with the difficulty ramping through the set.

The detail that changes how you play is the penalty. Reports consistently say a wrong answer costs a point, so a guess on a question you cannot see is a two-point swing against leaving it. On the arithmetic sprint you cannot skip, so the only defence is to answer accurately and accept that you will not reach the end. On the sequences module you can skip, and a skip is worth zero. For the rest of the process, including the language-quirk coding screen that technology-track candidates sit instead, see the Flow Traders online assessment guide and the Flow Traders interview process.

The format, as candidates report it

Section 1

Mental arithmetic, about 8 minutes. We run 40 questions, which is more than most candidates reach; the real screen is also reported to be unfinishable by design.

Section 2

Number sequences, about 25 minutes. We run 30 questions on an easy-to-hard ramp, roughly 50 seconds each.

Sep 2026 sitting

A candidate who advanced reports 26 sequences in 25 minutes, hosted on the same platform as the well-known practice site but noticeably harder. Families they saw: interleaved strands (one strand doubling, the other Fibonacci, e.g. 8, 8, 16, 24, 32, 56, next 64), a subtractive recurrence a(n) = a(n-2) - a(n-1) (47, 30, 17, 13, 50, 20, 30), a three-term Fibonacci a(n+1) = a(n) + a(n-1) + a(n-2), the mixed recurrence a(n+1) = 3 a(n-1) + a(n), an index-dependent rule a(n+1) = a(n) n/2 - (n-1), primes starting high (41, 47, ...), fraction sequences whose differences alternate +1/2, -2/3, +3/4 shown in lowest terms (1, 1, 1/2, 1, 1, 9/8, ...), and differences running +2, -4, +8, -16 through the powers of two. They could not solve 3 or 4 of the hardest.

Answering

Four options on arithmetic, no skip, answer and advance. Five options on sequences, skip allowed, forward only.

Scoring

+1 correct, −1 wrong, 0 skipped or not reached, in both sections. Your total is the sum of the two section scores.

Maths

Integers, decimals and fractions; direct (47 × 8 = ?) and missing-operand (? × 6 = 13.8) shapes.

Sequences

Arithmetic, geometric, recurrences, interleaved pairs, operation cycles, difference ladders, fractions and power towers.

What the Flow Traders sequences test screen looks like

Candidate reports do not name a vendor for the trading screen, so it is not a HackerRank or Codility sitting in any report we have. What they describe is two timed modules in one sitting: a mental arithmetic sprint of about 8 minutes where you answer and advance with no skip and four options per question, then a sequences section of about 25 minutes with five options, a skip button and forward-only navigation. A wrong answer costs a point in both modules and a skip scores zero, so the screen rewards deciding quickly which questions to leave. Our Flow Traders OA guide also records a trader and junior developer screen of a different shape: about 7 multiple-choice questions on C++ and Python quirks, 3 coding problems and a couple of probability items, with a timed replica of the MCQ half.

For how this compares with the SHL, HackerRank, Codility, Criteria and Mettl screens other firms use, see which assessment platform each quant firm uses.

How to play a penalised numerical test

Estimate before you pick. Most options are built from the classic slips: off by one, off by ten, the wrong power of ten on a decimal, the fraction not reduced. A one-second magnitude check rules out half the board and protects you from the −1.
Reframe missing-operand questions instantly. ? × 6 = 13.8 is 13.8 / 6; 72 − ? = 29 is 72 − 29. The reflex is trainable and is where most lost seconds go.
On sequences, run the checklist in order. Differences, then ratios, then odd and even positions separately, then the standard ladders (squares, primes, Fibonacci), then digit tricks. Commit to the first rule that fits every gap.
Skip is a tool in section 2, not a failure. A skip is 0; a wrong answer is −1. If two options survive your checks and you cannot split them in ten seconds, move on and come back to your time budget, not to the question.

For the sequence taxonomy with worked examples, see number sequence tests in trading interviews. When the numbers feel solid, build out the rest of your Flow Traders prep:

Full Flow Traders OA guide → Flow Traders interview process Flow Traders interview questions

Practice every firm's OA: timed replicas, free game replicas and guides in one place →

Flow Traders sequences test: frequently asked questions

What is in the Flow Traders online assessment?

Candidates report a timed mental arithmetic section of about 8 minutes where most people do not finish, plus a separate number sequences section of roughly 25 minutes, both with a wrong-answer penalty. Separate reports for the trader and junior developer screen describe about 7 language-quirk multiple-choice questions on C++ and Python, 3 coding problems and a couple of probability questions.

How long is the Flow Traders sequences test?

About 25 minutes for the sequences section, after the arithmetic sprint of about 8 minutes. Flow Traders does not publish question counts, so this replica runs 30 sequences on an easy-to-hard ramp, roughly 50 seconds each, and 40 arithmetic questions, which is more than most candidates reach.

How is the Flow Traders numerical test scored?

Candidate reports describe penalty scoring, so a wrong answer costs what a right one earns and skipping is free. This replica uses plus one, minus one and zero in both sections and reports the two section scores and their total.

Does the Flow Traders OA include coding?

The trader and junior developer screen in our guide does: about 7 multiple-choice questions on uncommon C++ and Python behaviour (operator precedence, integer division, pre- and post-increment, list aliasing, default mutable arguments, short-circuit evaluation, char arithmetic), then 3 coding problems, 2 easy and 1 harder. The arithmetic and sequences modules on this page have no coding.

Is this Flow Traders OA practice free?

Yes. Both sections on this page run free with no account. Every question is generated from a rule and its answer is verified in code, and the end screen shows a per-family breakdown with the rule for every sequence you missed.

How this replica works

Section timing comes from candidate reports summarised on our guide pages: an 8-minute mental math section plus a longer sequences section of about 25 minutes. Flow Traders does not publish question counts or the scoring rule, so the 40 and 30 question counts and the +1 / −1 scheme are our reconstruction from the same reports; if you have sat a recent Flow Traders numerical test and something is off, tell us at [email protected]. Every question is generated fresh in your browser from a rule, the correct option is computed from that rule, and the page independently re-derives each answer before rendering it, so the option marked correct always is. On the sequences section, each shown prefix is additionally tested against a library of alternative pattern rules (differences, ratios, recurrences, interleaved strands, operation cycles, difference ladders), and any question whose visible terms also fit a second natural pattern with a different next term is discarded before you see it, so there is only one defensible answer.