IdioVol3F · Volatility · Ang et al. (2006)

Idiosyncratic risk (3 factor)

Long minus short decile portfolio, value-weighted, market-adjusted. Quarterly, 1926Q4 to 2024Q4.

Expected return · posterior mean, % per year, averaged over the window
Next quarter
2026Q4
15.62%
95% interval 9.10% to 21.55%
Next year
2026Q4–2027Q3
15.53%
95% interval 8.87% to 21.61%
Next five years
2026Q4–2031Q3
15.09%
95% interval 7.89% to 21.91%

Forecast made 16 Sep 2026, conditioning on this portfolio's OAP returns, which end 2024Q4. The 7 quarters between then and 2026Q4 are unobserved and are integrated out under the model.

Cumulative market-adjusted return

+74,182,985% since 1926Q4 · log scale

Past performance, annualized

Window Mean Vol. Sharpe t
1926Q4–2024Q4 17.48% 25.88% 0.68 6.70
2020Q1–2024Q4 25.73% 23.07% 1.12 2.49
2024Q1–2024Q4 4.60% 36.96% 0.12 0.12

Forecast Sharpe ratio, annualized

Window Mean 95% interval P(neg)
2026Q4 0.61 0.35 – 0.84 <0.01
2026Q4–2027Q3 0.55 0.30 – 0.78 <0.01
2026Q4–2031Q3 0.42 0.20 – 0.67 <0.01
Category
Volatility
Form
Continuous
Data
Price
Sorted on
Low minus high
Names per leg
480 long / 480 short median · 73 at the 10th pctile
Original sample
1963–2000