Pairs Trading Statistics Interview Guide
Pairs trading statistics interview guide for related assets, spreads, mean reversion, cointegration, costs, validation, and mistakes.
Candidates discussing spreads, mean reversion, and validation.
Pairs trading starts with a relationship
A pairs-trading prompt usually asks whether two related assets have a spread that can be modeled or traded. The statistical relationship must be justified, not assumed from similarity alone.
Mean reversion needs evidence
If the spread moves away from its typical level, the strategy idea is that it may revert. That idea depends on stability, entry and exit rules, costs, and risk limits.
Concrete example
A spread that reverted historically may stop reverting after a structural change. A strong answer asks how the pair was selected and whether performance survives out-of-sample periods.
Costs and sizing matter
Even a statistically stable spread can be unattractive after transaction costs, borrow costs, slippage, or capacity limits. Trading validity is stricter than statistical interest.
Common mistakes
Candidates often propose pairs because two names are similar. In interviews, explain the statistical test, selection process, and why the relationship should persist.
Practice the pattern
Use the LeetQuidity curriculum and calibration to turn this topic into a focused practice plan.