Stochastic Processes quant interview questions

Stochastic processes questions are standard in quant research and derivatives interviews. Expect random walks, gambler's ruin, Markov chains, martingales and optional stopping, Poisson processes and Brownian motion, including first-passage times and reflection arguments. The best answers recognise the right tool quickly: a martingale to avoid summing a series, or a recursion on states to get an expected hitting time. These problems are also the bridge to option pricing, where Itô calculus and risk-neutral expectations appear. The list below builds from discrete random walks to continuous-time questions with interviewer follow-ups. Free problems include hints and complete worked solutions with every step justified. Use them to practise the method-recognition skill interviewers care about, then try harder variants with the Generate tool.