Rough Martingale Optimal Transport: Theory, Implementation, and Regulatory Applications for Non-Modelable Risk Factors

The Fundamental Review of the Trading Book (FRTB) poses a significant challenge for exotic derivatives pricing, particularly for non-modelable risk factors (NMRF) where sparse market data leads to infinite audit bounds under classical Martingale Optimal Transport (MOT). We propose a unified Rough Ma

January 24, 2026 · 2 min · thequant.space

VIX and European options with jumps in the short-maturity regime

We present a study of the short-maturity asymptotics for VIX and European option prices in local-stochastic volatility models with compound Poisson jumps. Both out-of-the-money (OTM) and at-the-money (ATM) asymptotics are considered. The leading-order asymptotics are obtained in closed-form. We appl

January 24, 2026 · 2 min · thequant.space

Brownian ReLU(Br-ReLU): A New Activation Function for a Long-Short Term Memory (LSTM) Network

Deep learning models are effective for sequential data modeling, yet commonly used activation functions such as ReLU, LeakyReLU, and PReLU often exhibit gradient instability when applied to noisy, non-stationary financial time series. This study introduces BrownianReLU, a stochastic activation funct

January 23, 2026 · 2 min · thequant.space

Directional-Shift Dirichlet ARMA Models for Compositional Time Series with Structural Break Intervention

Compositional time series frequently exhibit structural breaks due to external shocks, policy changes, or market disruptions. Standard methods either ignore such breaks or handle them through fixed effects that cannot extrapolate beyond the sample, or step-function dummies that impose instantaneous

January 23, 2026 · 2 min · thequant.space

Network Security under Heterogeneous Cyber-Risk Profiles and Contagion

Cyber risk has become a critical financial threat in today’s interconnected digital economy. This paper introduces a cyber-risk management framework for networked digital systems that combines the strategic behavior of players with contagion dynamics within a security game. We address the problem of

January 23, 2026 · 2 min · thequant.space

A Nonlinear Target-Factor Model with Attention Mechanism for Mixed-Frequency Data

We propose Mixed-Panels-Transformer Encoder (MPTE), a novel framework for estimating factor models in panel datasets with mixed frequencies and nonlinear signals. Traditional factor models rely on linear signal extraction and require homogeneous sampling frequencies, limiting their applicability to

January 22, 2026 · 2 min · thequant.space

Design and Empirical Study of a Large Language Model-Based Multi-Agent Investment System for Chinese Public REITs

This study addresses the low-volatility Chinese Public Real Estate Investment Trusts (REITs) market, proposing a large language model (LLM)-driven trading framework based on multi-agent collaboration. The system constructs four types of analytical agents-announcement, event, price momentum, and mark

January 22, 2026 · 2 min · thequant.space

Impact of LLMs news Sentiment Analysis on Stock Price Movement Prediction

This paper addresses stock price movement prediction by leveraging LLM-based news sentiment analysis. Earlier works have largely focused on proposing and assessing sentiment analysis models and stock movement prediction methods, however, separately. Although promising results have been achieved, a c

January 22, 2026 · 2 min · thequant.space

Prediction Markets as Bayesian Inverse Problems: Uncertainty Quantification, Identifiability, and Information Gain from Price-Volume Histories under Latent Types

Prediction markets are often described as mechanisms that ``aggregate information’’ into prices, yet the mapping from dispersed private information to observed market histories is typically noisy, endogenous, and shaped by heterogeneous and strategic participation. This paper formulates prediction m

January 22, 2026 · 2 min · thequant.space

The GT-Score: A Robust Objective Function for Reducing Overfitting in Data-Driven Trading Strategies

Overfitting remains a critical challenge in data-driven financial modeling, where machine learning (ML) systems learn spurious patterns in historical prices and fail out of sample and in deployment. This paper introduces the GT-Score, a composite objective function that integrates performance, stati

January 22, 2026 · 2 min · thequant.space

Beyond Carr Madan: A Projection Approach to Risk-Neutral Moment Estimation

We propose a projection method to estimate risk-neutral moments from option prices. We derive a finite-sample bound implying that the projection estimator attains (up to a constant) the smallest pricing error within the span of traded option payoffs. This finite-sample optimality is not available fo

January 21, 2026 · 2 min · thequant.space

Demystifying the trend of the healthcare index: Is historical price a key driver?

Healthcare sector indices consolidate the economic health of pharmaceutical, biotechnology, and healthcare service firms. The short-term movements in these indices are closely intertwined with capital allocation decisions affecting research and development investment, drug availability, and long-ter

January 20, 2026 · 2 min · thequant.space

Infinite-Dimensional LQ Mean Field Games with Common Noise: Small and Arbitrary Finite Time Horizons

We extend the results of (Liu and Firoozi, 2025), which develops the theory of linear-quadratic (LQ) mean field games (MFGs) in Hilbert spaces, by incorporating a common noise. This common noise is modeled as an infinite-dimensional Wiener process affecting the dynamics of all agents. In the presenc

January 20, 2026 · 2 min · thequant.space

Leveraged positions on decentralized lending platforms

We develop a mathematical framework to optimize leveraged staking (“loopy”) strategies in Decentralized Finance (DeFi), in which a staked asset is supplied as collateral, the underlying is borrowed and re-staked, and the loop can be repeated across multiple lending markets. Exploiting the fact that

January 20, 2026 · 2 min · thequant.space

Log-optimality with small liability stream

In an incomplete financial market with general continuous semimartingale dynamics; we model an investor with log-utility preferences who, in addition to an initial capital, receives units of a non-traded endowment process. Using duality techniques, we derive the fourth-order expansion of the primal

January 20, 2026 · 2 min · thequant.space

Look-Ahead-Bench: a Standardized Benchmark of Look-ahead Bias in Point-in-Time LLMs for Finance

We introduce Look-Ahead-Bench, a standardized benchmark measuring look-ahead bias in Point-in-Time (PiT) Large Language Models (LLMs) within realistic and practical financial workflows. Unlike most existing approaches that primarily test inner lookahead knowledge via Q&A, our benchmark evaluates mo

January 20, 2026 · 2 min · thequant.space

Test-Time Adaptation for Non-stationary Time Series: From Synthetic Regime Shifts to Financial Markets

Time series encountered in practice are rarely stationary. When the data distribution changes, a forecasting model trained on past observations can lose accuracy. We study a small-footprint test-time adaptation (TTA) framework for causal timeseries forecasting and direction classification. The backb

January 20, 2026 · 2 min · thequant.space

Variational Quantum Circuit-Based Reinforcement Learning for Dynamic Portfolio Optimization

This paper presents a Quantum Reinforcement Learning (QRL) solution to the dynamic portfolio optimization problem based on Variational Quantum Circuits. The implemented QRL approaches are quantum analogues of the classical neural-network-based Deep Deterministic Policy Gradient and Deep Q-Network al

January 20, 2026 · 2 min · thequant.space

A Learnable Wavelet Transformer for Long-Short Equity Trading and Risk-Adjusted Return Optimization

Learning profitable intraday trading policies from financial time series is challenging due to heavy noise, non-stationarity, and strong cross-sectional dependence among related assets. We propose \emph{WaveLSFormer}, a learnable wavelet-based long-short Transformer that jointly performs multi-scale

January 19, 2026 · 2 min · thequant.space

Beyond Visual Realism: Toward Reliable Financial Time Series Generation

Generative models for financial time series often create data that look realistic and even reproduce stylized facts such as fat tails or volatility clustering. However, these apparent successes break down under trading backtests: models like GANs or WGAN-GP frequently collapse, yielding extreme and

January 19, 2026 · 2 min · thequant.space