√252
Definition · Level 11 · Interview practice
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≈ 15.87 — the factor between daily and annual volatility on trading days: annual σ = daily σ × 15.87.
Example
1% daily vol ≈ 15.9% annualised.
Where Tradecraft teaches it
Level 11 · Interview practice, in the lesson “Mental math toolkit”: Near-100 products, squares, fraction tables, compounding, square roots and basis points — the shortcuts behind fast answers.
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