arXiv Machine Learning

M3: A State-Event Generative Foundation Model for Market Microstructure Dynamics

arXiv:2608. 19227v1 Announce Type: cross Abstract: Market microstructure simulation aims to model how liquidity, prices, and order flow evolve in electronic financial markets.

arXiv AI
Sep 28

Agentic Limit Order Books: Phase Transitions and Market Impact

The paper studies Limit Order Books (LOBs) that are populated only by autonomous reinforcement‑learning agents. It shows that such agentic LOBs exhibit clear phase boundaries between orderly price discovery and hyper‑volatile cascade states, determined by critical thresholds in agent number and market depth. Additionally, it finds that market impact in these systems departs from the classic square‑root law, revealing distinct dissipative, balanced, and non‑dissipative regimes driven by nonlinear feedback loops.

By Jan Rosenzweig
arXiv AI
Jul 1

FinPersona-Bench: A Benchmark for Longitudinal Psychometric Stability of Autonomous Financial Agents

arXiv:2606. 31522v1 Announce Type: cross Abstract: Large Language Models (LLMs) are increasingly deployed as autonomous financial agents initialized with explicit behavioral mandates such as "preserve capital" or "avoid speculative bets" that are meant to govern every decision throughout deployment.

By Muhammad Usman Safder (Steve), Ayesha Gull (Steve), Rania Elbadry (Steve), Fan Zhang (Steve), Yankai Chen (Steve), Xueqing Peng (Steve), Xue (Steve), Liu, Preslav Nakov, Zhuohan Xie
arXiv AI
Sep 17

SAiFE-gym: Model-based Environments for Automated Market Making with Concentrated Liquidity

SAiFE-gym is a Python module that offers simulation environments for studying trading in Constant Product Markets with Concentrated Liquidity. It decomposes the microstructure of these markets into interactive components, allowing researchers to model various economic settings. The environments are vectorized for scalability in high‑dimensional reinforcement learning workflows, and the paper demonstrates their usefulness by evaluating RL agents under uncertain market parameters.

By Georgios Chionas, Charalampos Kleitsikas, Stefanos Leonardos, Leandro S\'anchez-Betancourt, Carmine Ventre
arXiv AI
Sep 15

Are LLMs Good Financial User Simulators? A Preliminary Study

Large language models (LLMs) are being tested as simulators of individual financial decision-making. In a controlled paper‑trading experiment with 120 volunteers, the study evaluated whether an LLM could predict a participant’s next‑day trading action, chosen security, and transaction size using only pre‑cutoff information. Results showed that including market context improved predictions of actions and tickers, but sizing remained challenging, and the models tended to over‑predict hold actions, under‑predict sells, and simplify multi‑security trades.

By Jiajie He, Jiangyuan Hong, Dongling Ni, Wenjin Liu, Xintong Chen
arXiv Machine Learning
Sep 14

FINESSE: An Agent-Based Simulator and Benchmark Dataset for Multimodal Financial Event Sequences

FINESSE is an agent‑based simulation framework that generates synthetic, structured datasets of multiple interdependent financial event streams, such as transactions, payments, account status changes, and policy interventions. Each stream has its own action space, schema, and variable types, and the streams are coupled through agents’ evolving latent states, allowing temporally rich interactions. The accompanying FINESSE‑Bench dataset supports four tasks—balance forecasting, transaction fraud detection, missed payment prediction, and next event prediction—and baseline results are provided using various time‑series and event‑sequence methods.

By Tyler Farnan, Benjamin Eng, Adam Abate, Xirui Hou, Rizal Fathony, Nam H. Nguyen, Senthil Kumar
arXiv Machine Learning
Sep 22

Robust Market Making with Hawkes Order Flow and Price Impact via Adversarial Reinforcement Learning

The paper proposes an adversarial reinforcement‑learning framework for market making that incorporates Hawkes‑process driven order arrivals and trade‑induced price impact, addressing limitations of prior Poisson‑based models. An LSTM module captures temporal dependencies in recent observations to handle increased non‑stationarity, and the authors analyze equilibrium properties and introduce a robustness evaluation protocol focused on the left tail of returns. Experiments across diverse market regimes demonstrate that the method improves left‑tail performance, especially under strong Hawkes excitation and moderate price impact, without relying on a terminal inventory bias.

By Hao Yang, Zhenguo Xu