no code implementations • 29 Jan 2024 • Kei Nakagawa, Kohei Hayashi, Yugo Fujimoto
This approach incorporates fractional Brownian motion~(fBm) to effectively identify positive or negative correlations in topic and word distribution over time, revealing long-term dependency or roughness.
no code implementations • 20 Sep 2023 • Kei Nakagawa, Masaya Abe, Seiichi Kuroki
However, the instability associated with the input parameter changes and estimation errors can deteriorate portfolio performance.
no code implementations • 31 Oct 2022 • Yugo Fujimoto, Kei Nakagawa, Kentaro Imajo, Kentaro Minami
Machine learning-based stock prediction methods including the TC method have been concentrating on point prediction.
no code implementations • 21 Feb 2022 • Yusuke Uchiyama, Kei Nakagawa
However, since it is difficult to estimate the expected return and the out-of-sample performance of the mean-variance portfolio is poor, risk-based portfolio construction methods focusing only on risk have been proposed, and are attracting attention mainly in practice.
no code implementations • 16 Jan 2022 • Kohei Hayashi, Kei Nakagawa
It generalizes the neural stochastic differential equation model by using fractional Brownian motion with a Hurst index larger than half, which exhibits the LRD property.
no code implementations • 28 Dec 2021 • Ruixing Cao, Akifumi Okuno, Kei Nakagawa, Hidetoshi Shimodaira
For correcting the asymptotic bias with fewer observations, this paper proposes a \emph{local radial regression (LRR)} and its logistic regression variant called \emph{local radial logistic regression~(LRLR)}, by combining the advantages of LPoR and MS-$k$-NN.
2 code implementations • 2 Mar 2021 • Shota Imaki, Kentaro Imajo, Katsuya Ito, Kentaro Minami, Kei Nakagawa
Deep hedging (Buehler et al. 2019) is a versatile framework to compute the optimal hedging strategy of derivatives in incomplete markets.
no code implementations • 15 Feb 2021 • Junpei Komiyama, Masaya Abe, Kei Nakagawa, Kenichiro McAlinn
We achieve superior statistical power to existing methods and prove that the false discovery rate is controlled.
1 code implementation • 18 Dec 2020 • Katsuya Ito, Kentaro Minami, Kentaro Imajo, Kei Nakagawa
We show the effectiveness of our method by conducting experiments on real market data.
no code implementations • 14 Dec 2020 • Kentaro Imajo, Kentaro Minami, Katsuya Ito, Kei Nakagawa
In this study, we propose a novel method of constructing a portfolio based on predicting the distribution of a financial quantity called residual factors, which is known to be generally useful for hedging the risk exposure to common market factors.
no code implementations • 3 Oct 2020 • Masahiro Kato, Kei Nakagawa, Kenshi Abe, Tetsuro Morimura
To achieve this purpose, we train an agent to maximize the expected quadratic utility function, a common objective of risk management in finance and economics.
no code implementations • 28 Sep 2020 • Masahiro Kato, Kei Nakagawa
In this paper, we suggest expected quadratic utility maximization (EQUM) as a new framework for policy gradient style reinforcement learning (RL) algorithms with mean-variance control.
no code implementations • 28 Apr 2020 • Kei Nakagawa, Shuhei Noma, Masaya Abe
In order to improve this problem, we propose RM-CVaR: Regularized Multiple $\beta$-CVaR Portfolio.
no code implementations • 17 Feb 2020 • Masaya Abe, Kei Nakagawa
We perform empirical analysis in the Japanese stock market and confirm the profitability of our framework.
no code implementations • 29 Jan 2020 • Yusuke Uchiyama, Kei Nakagawa
By comparing these portfolios, we confirm the proposed portfolio outperforms that of the existing Gaussian process latent variable model.
no code implementations • 2 Oct 2019 • Kei Nakagawa, Masaya Abe, Junpei Komiyama
Stock return predictability is an important research theme as it reflects our economic and social organization, and significant efforts are made to explain the dynamism therein.
no code implementations • 20 Jan 2019 • Kei Nakagawa, Tomoki Ito, Masaya Abe, Kiyoshi Izumi
Specifically, we extend the linear multi-factor model to be non-linear and time-varying with LSTM.