Joshua Della Vedova

Market Efficiency Trend

Weekly R-squared of the one-parameter Prelec fit applied to active retail trades.

As of 2026-04-20, the fit R-squared was 0.895, with a 52-week rolling z-score of -1.72. 13-week moving average: 0.936.

Weekly history

R-squared by wallet class (latest week)

Wallet classR-squared
Algorithmic0.887
Active Retail0.895
Sophisticated0.922
Casualn/a
One-Shotn/a

Methodology

Each week, for each wallet class, we fit a one-parameter Prelec weighting function to that class's pooled price-vs-realized-frequency scatter. The R-squared captures how well a single behavioral parameter describes that week's calibration gap. Higher values indicate a smooth, predictable distortion curve; lower values indicate that the week's mispricing is dominated by idiosyncratic shocks rather than a stable behavioral signature.

The headline index uses the active-retail R-squared because active retail is the largest human wallet cohort and most closely represents how well human beliefs price the market. The algorithmic R-squared is shown for comparison but can be noisy because algorithmic trading is more strategic than belief-driven.

Data

efficiency_history.csv · efficiency_latest.json · efficiency_timeseries.json

Cite

@misc{dellavedova2026efficiency, title = {Market Efficiency Trend}, author = {Della Vedova, Joshua}, year = {2026}, version = {0.1.0}, url = {https://jdellavedova.com/efficiency} }