Stabilising Lifetime PD Models under Forecast Uncertainty

Estimating lifetime probabilities of default (PDs) under IFRS~9 and CECL requires projecting point–in–time transition matrices over multiple years. A persistent weakness is that macroeconomic forecast errors compound across horizons, producing unstable and volatile PD term structures. This paper r

September 12, 2025 · 2 min · thequant.space

The Interplay between Utility and Risk in Portfolio Selection

We revisit the problem of portfolio selection, where an investor maximizes utility subject to a risk constraint. Our framework is very general and accommodates a wide range of utility and risk functionals, including non-concave utilities such as S-shaped utilities from prospect theory and non-convex

September 12, 2025 · 2 min · thequant.space

Ultrafast Extreme Events: Empirical Analysis of Mechanisms and Recovery in a Historical Perspective

To understand the emergence of Ultrafast Extreme Events (UEEs), the influence of algorithmic trading or high-frequency traders is of major interest as they make it extremely difficult to intervene and to stabilize financial markets. In an empirical analysis, we compare various characteristics of UEE

September 12, 2025 · 2 min · thequant.space

Bitcoin Price Forecasting Based on Hybrid Variational Mode Decomposition and Long Short Term Memory Network

This study proposes a hybrid deep learning model for forecasting the price of Bitcoin, as the digital currency is known to exhibit frequent fluctuations. The models used are the Variational Mode Decomposition (VMD) and the Long Short-Term Memory (LSTM) network. First, VMD is used to decompose the or

September 11, 2025 · 2 min · thequant.space

Causal PDE-Control for Adaptive Portfolio Optimization under Partial Information

Classical portfolio models tend to degrade under structural breaks, whereas flexible machine-learning allocators often lack arbitrage consistency and interpretability. We propose Causal PDE-Control Models (CPCMs), a framework that links structural causal drivers, nonlinear filtering, and forward-bac

September 11, 2025 · 2 min · thequant.space

DeepAries: Adaptive Rebalancing Interval Selection for Enhanced Portfolio Selection

We propose DeepAries , a novel deep reinforcement learning framework for dynamic portfolio management that jointly optimizes the timing and allocation of rebalancing decisions. Unlike prior reinforcement learning methods that employ fixed rebalancing intervals regardless of market conditions, DeepAr

September 11, 2025 · 2 min · thequant.space

Digital Transformation and Corporate Financial Asset Allocation: Evidence from China

Against the backdrop of rapid technological advancement and the deepening digital economy, this study examines the causal impact of digital transformation on corporate financial asset allocation in China. Using data from A-share listed companies from 2010 to 2022, we construct a firm-level digitaliz

September 11, 2025 · 2 min · thequant.space

Long memory score-driven models as approximations for rough Ornstein-Uhlenbeck processes

This paper investigates the continuous-time limit of score-driven models with long memory. By extending score-driven models to incorporate infinite-lag structures with coefficients exhibiting heavy-tailed decay, we establish their weak convergence, under appropriate scaling, to fractional Ornstein-U

September 11, 2025 · 2 min · thequant.space

Note on pre-taxation reported data by UK FTSE-listed companies. A search for Benford's laws compatibility

Pre-taxation analysis plays a crucial role in ensuring the fairness of public revenue collection. It can also serve as a tool to reduce the risk of tax avoidance, one of the UK government’s concerns. Our report utilises pre-tax income ($PI$) and total assets ($TA$) data from 567 companies listed on

September 11, 2025 · 3 min · thequant.space

Optimal Investment and Consumption in a Stochastic Factor Model

In this article, we study optimal investment and consumption in an incomplete stochastic factor model for a power utility investor on the infinite horizon. When the state space of the stochastic factor is finite, we give a complete characterisation of the well-posedness of the problem, and provide a

September 11, 2025 · 2 min · thequant.space

Community-level Contagion among Diverse Financial Assets

As global financial markets become increasingly interconnected, financial contagion has developed into a major influencer of asset price dynamics. Motivated by this context, our study explores financial contagion both within and between asset communities. We contribute to the literature by examining

September 10, 2025 · 2 min · thequant.space

Environmental Performance, Financial Constraint and Tax Avoidance Practices: Insights from FTSE All-Share Companies

Through its initiative known as the Climate Change Act (2008), the Government of the United Kingdom encourages corporations to enhance their environmental performance with the significant aim of reducing targeted greenhouse gas emissions by the year 2050. Previous research has predominantly assessed

September 10, 2025 · 2 min · thequant.space

FinZero: Launching Multi-modal Financial Time Series Forecast with Large Reasoning Model

Financial time series forecasting is both highly significant and challenging. Previous approaches typically standardized time series data before feeding it into forecasting models, but this encoding process inherently leads to a loss of important information. Moreover, past time series models genera

September 10, 2025 · 2 min · thequant.space

A Stochastic Model for Illiquid Stock Prices and its Conclusion about Correlation Measurement

This study explores the behavioral dynamics of illiquid stock prices in a listed stock market. Illiquidity, characterized by wide bid and ask spreads affects price formation by decoupling prices from standard risk and return relationships and increasing sensitivity to market sentiment. We model the

September 9, 2025 · 2 min · thequant.space

Chaotic Bayesian Inference: Strange Attractors as Risk Models for Black Swan Events

We introduce a new risk modeling framework where chaotic attractors shape the geometry of Bayesian inference. By combining heavy-tailed priors with Lorenz and Rossler dynamics, the models naturally generate volatility clustering, fat tails, and extreme events. We compare two complementary approaches

September 9, 2025 · 1 min · thequant.space

Hedging Options on Asset Portfolios against Just One Underlying Asset in the Presence of Transaction Costs

Options are contingent claims regarding the value of underlying assets. The Black-Scholes formula provides a road map for pricing these options in a risk-neutral setting, justified by a delta hedging argument in which countervailing positions of appropriate size are taken in the underlying asset. Ho

September 9, 2025 · 2 min · thequant.space

Joint calibration of the volatility surface and variance term structure

This article proposes a calibration framework for complex option pricing models that jointly fits market option prices and the term structure of variance. Calibrated models under the conventional objective function, the sum of squared errors in Black-Scholes implied volatilities, can produce model-i

September 9, 2025 · 2 min · thequant.space

Machine Learning with Multitype Protected Attributes: Intersectional Fairness through Regularisation

Ensuring equitable treatment (fairness) across protected attributes (such as gender or ethnicity) is a critical issue in machine learning. Most existing literature focuses on binary classification, but achieving fairness in regression tasks-such as insurance pricing or hiring score assessments-is eq

September 9, 2025 · 2 min · thequant.space

Geometric Dynamics of Consumer Credit Cycles: A Multivector-based Linear-Attention Framework for Explanatory Economic Analysis

This study introduces geometric algebra to decompose credit system relationships into their projective (correlation-like) and rotational (feedback-spiral) components. We represent economic states as multi-vectors in Clifford algebra, where bivector elements capture the rotational coupling between un

September 8, 2025 · 2 min · thequant.space

Nested Optimal Transport Distances

Simulating realistic financial time series is essential for stress testing, scenario generation, and decision-making under uncertainty. Despite advances in deep generative models, there is no consensus metric for their evaluation. We focus on generative AI for financial time series in decision-makin

September 8, 2025 · 2 min · thequant.space