Susquehanna is the firm that will ask about your worst decision that worked out fine. Where other trading interviews probe whether you can compute, SIG's reputation is for probing whether you can decide: with incomplete information, with real variance, and with the humility to separate a good process from a lucky outcome. The poker culture is not marketing; candidates consistently report it shaping the questions themselves.
Two things before the walkthrough. QuantPit is independent and unaffiliated with Susquehanna, and everything below reflects what candidates publicly and repeatedly report, not an official process description. Nothing here reproduces a real question. Details differ by role, office, and year, so treat this as terrain, not a script. Our SIG firm page keeps the same picture next to practice sets in the firm's style.
The philosophy that shapes every round
One idea explains most of the SIG interview: outcome is not the same as decision quality. A trader who takes a bet with positive expected value and loses made a good decision. A trader who takes a terrible bet and wins made a bad one and got paid anyway. Markets, like poker, pay out on a delay and add noise on top, so the only thing a firm can select for at interview is the quality of the reasoning.
This has a practical consequence for you. When you are asked about a decision, from a poker hand to a class project to a bad trade you once made, the answer that scores is the one that reconstructs what you knew at the time, what the alternatives were, and what the expected values looked like before the result arrived. "It worked out" is not an answer, and neither is "it failed, so it was wrong."
The stages candidates describe
First filter: assessment or recruiter screen
Depending on role and region, candidates report either an online assessment (math, logic, sometimes a game-flavored component) or a recruiter conversation first. The assessment families here are the standard ones, covered in our assessment formats guide: speed arithmetic, probability quizzes, and pattern work. Prepare for the family, not the firm.
The probability and betting rounds
The core rounds are conversations with traders, and the questions arrive dressed as bets more often than as problems. You will be asked what you would pay for something, what odds you need, whether you take one side or the other, and how much you would size. The underlying mathematics is standard, conditional probability, expected value, combinatorics, but the framing keeps converting your beliefs into commitments.
Two habits pay off here. First, always finish the arithmetic with a decision: fair value is 3, so I buy below 2.80, I sell above 3.20, and I would size this at a fraction of my bankroll because the variance is high. Second, quantify uncertainty out loud: I am confident to within about 10%, and here is what would change my number. Practice both in the expected value and probability topic sets.
Poker and game questions
Candidates often report poker coming up directly: hand analysis, pot odds, or simply whether you play and what you have learned. You do not need to be a serious player, and pretending to be one is a bad trade. What you do need is the vocabulary of the underlying ideas, because they are trading ideas wearing a card-game costume:
- Pot odds and break-even frequency. If calling 20 into a pot of 100 needs to work about one time in six to break even, you have computed a threshold probability. That is the same calculation as pricing an option or taking a bet at posted odds.
- Bet sizing and bankroll. How much to risk when you have an edge is the Kelly criterion question, and it is a genuine SIG-adjacent topic worth understanding properly rather than quoting.
- Information and adverse selection. In poker, someone calling your big bet usually has something. In markets, the person hitting your bid usually knows something. The market making questions test whether that intuition is live for you.
- Variance tolerance. Being right 55% of the time means long losing stretches. Candidates who visibly understand this read as tradeable; candidates who treat every loss as an error do not.
Later rounds and the final stage
Reports describe multiple rounds, sometimes several in one day, mixing harder probability, market-making style games where you quote two-sided prices, mental arithmetic under time pressure, and behavioral conversations that keep returning to decisions under uncertainty. The mental math base matters throughout, because a candidate who stalls on arithmetic cannot demonstrate anything else.
What to prepare, in priority order
- Expected value fluency. Not the formula, the reflex: decompose, compute, sanity-check, convert to a decision. Start at /topics/expected-value/.
- Conditional probability without traps. The classic failure mode is conditioning on the wrong event. Drill until the counting is automatic at /topics/probability/.
- Bet sizing and risk. Understand edge, odds, and why full-Kelly sizing is aggressive in practice. Our Kelly guide covers the derivation and the sanity checks.
- Two or three decision stories. Prepared, honest, and structured around what you knew at the time. One where the outcome was bad and the decision was right is worth more than three success stories.
- Arithmetic maintenance. Fifteen minutes daily; measure yourself on the free 80 in 8 benchmark even though the format is another firm's, because the underlying speed is universal.
Common ways candidates lose points
Answering the math and stopping. The question is nearly always "what do you do," not "what is the number."
Defending a wrong answer. Updating fast and cleanly is the trait being measured; digging in destroys the signal.
Fake confidence. Saying "definitely" about something you are 70% sure of is a calibration failure, and this is the one firm most likely to notice.
Treating poker questions as trivia. They are decision questions. Answer them with reasoning, not with results.
FAQ
Do I need to play poker to get an offer at SIG?
No. Candidates without poker backgrounds are hired regularly. What helps is understanding the concepts poker teaches, pot odds, bet sizing, variance, and information asymmetry, all of which you can learn without ever playing a hand.
How mathematical are SIG trading interviews?
The mathematics is mostly undergraduate probability and expected value rather than advanced theory, but the application is demanding: fast, out loud, and converted into decisions. Research roles carry a higher mathematical bar than trading roles.
What is the difference between a good decision and a good outcome?
A good decision uses the information available to choose the option with the best expected value; a good outcome is simply what happened afterward. Because variance is large in trading, the two often disagree, and SIG interviews are widely reported to probe whether candidates can tell them apart.
How long is the SIG interview process?
Candidates commonly describe several weeks from application to final decision, with multiple rounds and sometimes a final day of back-to-back interviews. Timelines compress during peak season; see the 2026-27 cycle timeline for how the season is structured.
What should I practice the week before?
Timed expected-value questions, spoken out loud, plus one full mock round. Cramming new material late helps less than rehearsing the delivery of material you already know, which is the actual bottleneck in a conversational interview.