SIG / Susquehanna Online Assessment Guide

What the SIG OA Tests

SIG's online assessment covers four areas, each reflecting how SIG thinks about trading and decision-making:

• Mental math speed. Timed arithmetic — multiplication, percentages, fractions — similar in format to the Optiver 80-in-8 test. Speed is as important as accuracy.
• Probability and expected value. Coin flips, dice problems, geometric distributions, and fair game pricing. SIG's poker culture means they specifically test whether you can evaluate bets quickly.
• Options basics. Call and put payoffs, put-call parity, and directional intuition on how option prices move. Not Black-Scholes derivations — directional reasoning.
• Game theory and strategic thinking. Simplified poker hands, Nash equilibria concepts, and problems where the optimal strategy depends on your opponent's reasoning. SIG is deeply poker-influenced.

The assessment typically runs 30 to 60 minutes and is timed at the individual question level. A candidate who is methodical but slow will be filtered out even if every answer is correct.

Mental Math Section

The mental math component is non-negotiable. You may face:

• Two- and three-digit multiplication (e.g., 37 × 48, 124 × 17)
• Percentage calculations (e.g., 17.5% of 240)
• Fraction simplification and mental division
• Quick powers of 2 and small primes (know 2¹ through 2¹², squares up to 25²)

Practice tips: Drill multiplication tables with a stopwatch — you want two-digit multiplication under 10 seconds. Use the left-to-right multiplication method: 37 × 48 = 37 × 40 + 37 × 8 = 1480 + 296 = 1776. For percentages, convert to fractions when possible: 37.5% = 3/8, so 37.5% of 240 = 3/8 × 240 = 90. Speed comes from pattern recognition, not raw calculation.

SIG is one of the firms most known for testing arithmetic speed. Candidates who have not drilled this systematically are almost always eliminated at this stage — regardless of their math background.

Probability Section

The probability questions follow a predictable set of patterns. Every candidate should be fluent in:

• Geometric distribution. “Expected number of rolls until a 6” = 6. “Expected flips until heads” = 2. Recognize these instantly and apply E = 1/p.
• Conditional probability. “You roll two dice. Given the sum is greater than 7, what is the probability it equals 9?” Enumerate the conditional sample space explicitly.
• Fair game pricing. “What is the fair price of a game that pays $10 with probability 1/3 and $0 otherwise?” E[payoff] = $10 × 1/3 = $3.33. SIG loves asking whether you would play a game at a given price.
• Linearity of expectation. Problems that decompose into independent parts — expected sum, expected count, expected fixed points. Always look for indicator variables.

See the expected value problems guide for five fully worked examples including the coupon collector problem and the hat-check problem.

Options Basics Section

SIG is an options trading firm, so even the OA tests that you understand options directionally. You do not need to derive Black-Scholes, but you do need to answer questions like:

• Call and put payoffs. A call option pays max(S − K, 0) at expiry. A put pays max(K − S, 0). Draw the payoff diagrams in your head — long call, long put, covered call, protective put.
• Put-call parity. C − P = S − K · e^(−rT). If a $100-strike call trades at $5 and the stock is at $100 with one year to expiry at 0% rates, what should the put cost? P = C − S + K = 5 − 100 + 100 = $5. Violations of put-call parity imply arbitrage.
• Directional option intuition. If volatility increases, do calls go up or down? (Up — more vol means more optionality value.) If time to expiry decreases, does theta help or hurt a long option? (Hurts — time value decays toward zero.)
• Intrinsic vs. time value. A $95-strike call on a $100 stock has $5 intrinsic value. Any premium above that is time value, reflecting the possibility of further moves before expiry.

Game Theory Section

SIG's poker culture makes game theory a genuine differentiator. Expect simplified scenarios such as:

• A two-player game where each player chooses a number; the higher number wins but costs more to play — what is the Nash equilibrium?
• A card game where you see a partial hand and must decide whether to bet or fold given your opponent's possible holdings.
• Auctions where bidding your true value is or is not the dominant strategy (first-price vs. second-price auctions).

For these questions, look for dominant strategies first. If no dominant strategy exists, think about what a rational opponent would do given that you are also rational. SIG is not looking for advanced game theory — they want candidates who reason clearly under uncertainty.

How to Prepare: A Two-Week Timeline

The most common mistake candidates make is spending too much time on probability and options and not enough on mental math. Mental math speed is where most otherwise-prepared candidates fail.