AgeIPO · Other · Ritter (1991)

IPO and age

Long minus short decile portfolio, value-weighted, market-adjusted. Quarterly, 1981Q2 to 2024Q4.

Expected return · posterior mean, % per year, averaged over the window
Next quarter
2026Q4
10.72%
95% interval 2.42% to 19.64%
Next year
2026Q4–2027Q3
10.58%
95% interval 2.14% to 19.53%
Next five years
2026Q4–2031Q3
10.17%
95% interval 1.01% to 19.42%

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

+4,582% since 1981Q2 · log scale

Past performance, annualized

Window Mean Vol. Sharpe t
1981Q2–2024Q4 12.90% 28.77% 0.45 2.97
2020Q1–2024Q4 −6.64% 32.54% −0.20 −0.46
2024Q1–2024Q4 49.52% 6.92% 7.15 7.15

Forecast Sharpe ratio, annualized

Window Mean 95% interval P(neg)
2026Q4 0.37 0.08 – 0.69 0.01
2026Q4–2027Q3 0.35 0.07 – 0.64 0.01
2026Q4–2031Q3 0.30 0.03 – 0.60 0.02
Category
Other
Form
Continuous
Data
Event
Sorted on
High minus low
Names per leg
52 long / 72 short median · 24.7 at the 10th pctile
Original sample
1975–1987