Trading Graph Neural Network
Xian Wu
TL;DR
Trading Graph Neural Network (TGNN) addresses price formation in trading networks by jointly modeling asset features, dealer features, and relationship features within a structurally grounded graph-based estimator, yielding a unique equilibrium $\boldsymbol{v}^*$ found via a contraction mapping $T$. It blends the Simulated Method of Moments philosophy with neural graph learning to directly minimize prediction error and produce interpretable parameter estimates with bootstrap confidence intervals. Across dense, sparse, and core-periphery networks, TGNN outperforms traditional OLS with centrality controls and accurately recovers latent primitives such as bargaining power and holding costs, enabling counterfactual analyses in OTC and decentralized markets. By micro-founding the message-passing mechanism with economic structure, TGNN provides economists with a tool for price formation analysis, regulatory insight, and systemic-risk assessment in heterogeneous trading networks.
Abstract
This paper proposes a new algorithm -- Trading Graph Neural Network (TGNN) that can structurally estimate the impact of asset features, dealer features and relationship features on asset prices in trading networks. It combines the strength of the traditional simulated method of moments (SMM) and recent machine learning techniques -- Graph Neural Network (GNN). It outperforms existing reduced-form methods with network centrality measures in prediction accuracy. The method can be used on networks with any structure, allowing for heterogeneity among both traders and assets.
