Extreme Value Theory: Block Maxima & GEV — The Fisher-Tippett-Gnedenko theorem is the EVT analogue of the CLT: block maxima Mₙ = max(X₁,…,Xₙ), when normalized, converge to the Generalized Extreme Value distribution with shape ξ. ξ=0: Gumbel (light tails, e.g. Normal); ξ>0: Fréchet (heavy tails, e.g. Pareto); ξ<0: Weibull (bounded, e.g. Uniform). Applications: 100-year floods, financial tail risk.