# Quadratic variation & the Itô integral

SC003 · Stochastic Calculus · Chapter 3 of 6. Twelve interactive steps with a paced, recorded Coach–Zon conversation.

Build the stochastic integral from positions chosen before the move, then connect quadratic variation to realised variance.

Make a prediction, change a control, read the formula and explain what changed. This is a model-based mathematical lesson, not a forecast of market returns.

Canonical page: https://21ifm.com/quant/stochastic-calculus/quadratic-variation-ito-integral

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