Myopic Optimality: why reinforcement learning portfolio management strategies lose money

Myopic optimization (MO) outperforms reinforcement learning (RL) in portfolio management: RL yields lower or negative returns, higher variance, larger costs, heavier CVaR, lower profitability, and greater model risk. We model execution/liquidation frictions with mark-to-market accounting. Using Mall

September 16, 2025 · 2 min · thequant.space

Optimal Annuitization with stochastic mortality: Piecewise Deterministic Mortality Force

This paper addresses the problem of determining the optimal time for an individual to convert retirement savings into a lifetime annuity. The individual invests their wealth into a dividend-paying fund that follows the dynamics of a geometric Brownian motion, exposing them to market risk. At the sam

September 16, 2025 · 2 min · thequant.space

Strassen's theorem for biased convex order

Strassen’s theorem asserts that for given marginal probabilities $μ,ν$ there exists a martingale starting in $μ$ and terminating in $ν$ if and only if $μ,ν$ are in convex order. From a financial perspective, it guarantees the existence of market-consistent martingale pricing measures for arbitrage-f

September 16, 2025 · 2 min · thequant.space

Valuation of Exotic Options and Counterparty Games Based on Conditional Diffusion

This paper addresses the challenges of pricing exotic options and structured products, which traditional models often fail to handle due to their inability to capture real-world market phenomena like fat-tailed distributions and volatility clustering. We introduce a Diffusion-Conditional Probability

September 16, 2025 · 2 min · thequant.space

Bootstrapping Liquidity in BTC-Denominated Prediction Markets

Prediction markets have gained adoption as on-chain mechanisms for aggregating information, with platforms such as Polymarket demonstrating demand for stablecoin-denominated markets. However, denominating in non-interest-bearing stablecoins introduces inefficiencies: participants face opportunity co

September 15, 2025 · 2 min · thequant.space

Context-Aware Language Models for Forecasting Market Impact from Sequences of Financial News

Financial news plays a critical role in the information diffusion process in financial markets and is a known driver of stock prices. However, the information in each news article is not necessarily self-contained, often requiring a broader understanding of the historical news coverage for accurate

September 15, 2025 · 2 min · thequant.space

Dynamic Factor Models with Forward-Looking Views

Prediction models calibrated using historical data may forecast poorly if the dynamics of the present and future differ from observations in the past. For this reason, predictions can be improved if information like forward looking views about the state of the system are used to refine the forecast.

September 15, 2025 · 2 min · thequant.space

Group Survival Probability under Contagion in Microlending

In the context of micro-finance, a group of individuals undertake business projects that may interfere with one another. A contagious default happens if one person’s project failure leads to the default of another group member. In this paper, we apply a probabilistic approach to analyze the impact o

September 15, 2025 · 2 min · thequant.space

Meta-Learning Neural Process for Implied Volatility Surfaces with SABR-induced Priors

We treat implied volatility surface (IVS) reconstruction as a learning problem guided by two principles. First, we adopt a meta-learning view that trains across trading days to learn a procedure that maps sparse option quotes to a full IVS via conditional prediction, avoiding per-day calibration at

September 15, 2025 · 2 min · thequant.space

Reinforcement Learning-Based Market Making as a Stochastic Control on Non-Stationary Limit Order Book Dynamics

Reinforcement Learning has emerged as a promising framework for developing adaptive and data-driven strategies, enabling market makers to optimize decision-making policies based on interactions with the limit order book environment. This paper explores the integration of a reinforcement learning age

September 15, 2025 · 2 min · thequant.space

Sentiment Feedback in Equity Markets: Asymmetries, Retail Heterogeneity, and Structural Calibration

We study how sentiment shocks propagate through equity returns and investor clientele using four independent proxies with sign-aligned kappa-rho parameters. A structural calibration links a one standard deviation innovation in sentiment to a pricing impact of 1.06 basis points with persistence param

September 15, 2025 · 2 min · thequant.space

Enhancing ML Models Interpretability for Credit Scoring

Predicting default is essential for banks to ensure profitability and financial stability. While modern machine learning methods often outperform traditional regression techniques, their lack of transparency limits their use in regulated environments. Explainable artificial intelligence (XAI) has em

September 14, 2025 · 2 min · thequant.space

Mamba Outpaces Reformer in Stock Prediction with Sentiments from Top Ten LLMs

The stock market is extremely difficult to predict in the short term due to high market volatility, changes caused by news, and the non-linear nature of the financial time series. This research proposes a novel framework for improving minute-level prediction accuracy using semantic sentiment scores

September 14, 2025 · 2 min · thequant.space

Quantum and Classical Machine Learning in Decentralized Finance: Comparative Evidence from Multi-Asset Backtesting of Automated Market Makers

This study presents a comprehensive empirical comparison between quantum machine learning (QML) and classical machine learning (CML) approaches in Automated Market Makers (AMM) and Decentralized Finance (DeFi) trading strategies through extensive backtesting on 10 models across multiple cryptocurren

September 14, 2025 · 2 min · thequant.space

RegimeFolio: A Regime Aware ML System for Sectoral Portfolio Optimization in Dynamic Markets

Financial markets are inherently non-stationary, with shifting volatility regimes that alter asset co-movements and return distributions. Standard portfolio optimization methods, typically built on stationarity or regime-agnostic assumptions, struggle to adapt to such changes. To address these chall

September 14, 2025 · 2 min · thequant.space

Trading-R1: Financial Trading with LLM Reasoning via Reinforcement Learning

Developing professional, structured reasoning on par with human financial analysts and traders remains a central challenge in AI for finance, where markets demand interpretability and trust. Traditional time-series models lack explainability, while LLMs face challenges in turning natural-language an

September 14, 2025 · 2 min · thequant.space

Attribution Locus and the Timeliness of Long-lived Asset Write-downs

We examine the relative timeliness with which write-downs of long-lived assets incorporate adverse macroeconomic and industry outcomes versus adverse firm-specific outcomes. We posit that users of financial reports are more likely to attribute adverse firm-specific outcomes to suboptimal managerial

September 13, 2025 · 2 min · thequant.space

Why Bonds Fail Differently? Explainable Multimodal Learning for Multi-Class Default Prediction

In recent years, China’s bond market has seen a surge in defaults amid regulatory reforms and macroeconomic volatility. Traditional machine learning models struggle to capture financial data’s irregularity and temporal dependencies, while most deep learning models lack interpretability-critical for

September 13, 2025 · 2 min · thequant.space

Competition and Incentives in a Shared Order Book

Recent regulation on intraday electricity markets has led to the development of shared order books with the intention to foster competition and increase market liquidity. In this paper, we address the question of the efficiency of such regulations by analysing the situation of two exchanges sharing

September 12, 2025 · 2 min · thequant.space

Optimized Operation of Standalone Battery Energy Storage Systems in the Cross-Market Energy Arbitrage Business

The provision of renewable electricity is the foundation for a sustainable future. To achieve the goal of sustainable renewable energy, Battery Energy Storage Systems (BESS) could play a key role to counteract the intermittency of solar and wind generation power. In order to aid the system, the BESS

September 12, 2025 · 2 min · thequant.space