Leakage-Free Evaluation of a Meta-Learning Graph Neural Network for Cross-Sectional Equity Forecasting
Problem
Graph neural networks combined with meta-learning are increasingly proposed for financial forecasting and often reported to achieve strong risk-adjusted returns. Such results are extremely sensitive to evaluation methodology, and standard practice in this literature routinely violates temporal, informational, and accounting boundaries.
Method
MetaGraph couples a causal temporal encoder with a Meta-Relational Prior Network that conditions a biased graph-attention layer on time-varying correlation graphs of S&P 500 constituents, and adapts to the prevailing regime through first-order MAML. Training and evaluation target the cross-sectional Information Coefficient. A leakage-free protocol combines strict temporal splits with an embargo, past-only graphs, inference-time adaptation that mirrors training, non-overlapping holding-period accounting, and significance testing via stationary block bootstrap and deflated Sharpe ratio.
Contributions
- Leakage-free evaluation protocol for meta-learning GNNs on financial time series, with four specific safeguards.
- Documentation of four common evaluation errors (non-temporal splitting, overlapping-return accounting, ill-posed objectives, train/inference adaptation mismatch) that inflated an earlier version of this pipeline to an implausible Sharpe above 10.
- Honest test-set result under the corrected protocol, with full audit trail and reproducible pipeline.
- Co-authored with Sumitaa S Deshbhandari (Independent Researcher).