collaborators

5 papers

stat.ME2026

Nonconvex High-Dimensional Time-Varying Coefficient Estimation for Noisy High-Frequency Observations with a Factor Structure

Minseok Shin, Donggyu Kim

In this paper, we propose a novel high-dimensional time-varying coefficient estimator for noisy high-frequency observations with a factor structure. In high-frequency finance, we o…

stat.ME2025

Robust High-Dimensional Time-Varying Coefficient Estimation

Minseok Shin, Donggyu Kim

In this paper, we develop a novel high-dimensional coefficient estimation procedure based on high-frequency data. Unlike usual high-dimensional regression procedures such as LASSO,…

stat.ME2025

Factor and Idiosyncratic VAR Volatility Matrix Models for Heavy-Tailed High-Frequency Financial Observations

Minseok Shin, Donggyu Kim, Yazhen Wang +1

This paper introduces a novel process for both factor and idiosyncratic volatility matrices whose eigenvalues follow the vector auto-regressive (VAR) model. We call it the factor a…

cs.LG2025

Robust Reinforcement Learning under Diffusion Models for Data with Jumps

Chenyang Jiang, Donggyu Kim, Alejandra Quintos +1

Reinforcement Learning (RL) has proven effective in solving complex decision-making tasks across various domains, but challenges remain in continuous-time settings, particularly wh…

econ.EM2025

Matrix-based Prediction Approach for Intraday Instantaneous Volatility Vector

Sung Hoon Choi, Donggyu Kim

In this paper, we introduce a novel method for predicting intraday instantaneous volatility based on Ito semimartingale models using high-frequency financial data. Several studies…