Why the games are not a gimmick
Susquehanna states that "game theory and decision science are integral to our trading, our education, and our culture." On poker specifically: "We use poker to teach new traders about decision making under uncertainty", and "our traders go through similar thought processes while evaluating the expected value of a given trade and deciding how to price risk."
This is not marketing garnish. The firm employs World Series of Poker bracelet winners Bill Chen and Jerrod Ankenman, co-authors of The Mathematics of Poker, which it describes as "a leading introduction to quantitative techniques and game theory in poker." It also describes using chess, strategy games and team sports to develop the same skills, and devotes a substantial part of the same page to decision science - confirmation bias, anchoring, availability bias, framing - as things that distort trader judgement and market pricing.
Read that as a description of what the interviews are trying to measure. If a firm tells you it trains traders through expected-value reasoning under incomplete information, an interview built around bets, games and pricing decisions is the obvious consequence.
What that implies about the interviews
The firm does not publish a stage-by-stage process, so what follows is candidate reporting, and should be treated as such. Candidates commonly describe a timed quantitative screen early, then rounds built around probability, expected value and game-like scenarios - being asked to price something, take a side, and then defend or revise the decision when the situation changes.
The recurring theme in those reports matches what the firm says about itself: interviewers care about the quality of the decision and the reasoning behind it, not only the number at the end. Being talked out of a correct answer is a bad outcome; so is defending a wrong one past the point where the evidence turned.
What to prepare
Expected value until it is automatic. Not the formula - the habit of reaching for it, including on messy problems where the payoff structure is not handed to you.
Bet sizing and taking a side. Practise committing to a price or a decision and then updating it out loud as information arrives. Candidates who only compute, and never decide, interview badly here.
Bias awareness, genuinely. The firm names anchoring and confirmation bias on its own page. Noticing when a question is engineered to anchor you is a real advantage.
Poker, if you have the time. Not as a credential, but because a few hours of serious play teaches EV under uncertainty faster than reading about it does.
Practise the same formats
The question sets below are ours, written in the formats this process is reported to use. They are not Susquehanna's questions, and nothing here reproduces any part of its assessment.