{"title":"Dimensionality reduction techniques to support insider trading detection","authors":"Adele Ravagnani, Fabrizio Lillo, Paola Deriu, Piero Mazzarisi, Francesca Medda, Antonio Russo","doi":"arxiv-2403.00707","DOIUrl":"https://doi.org/arxiv-2403.00707","url":null,"abstract":"Identification of market abuse is an extremely complicated activity that\u0000requires the analysis of large and complex datasets. We propose an unsupervised\u0000machine learning method for contextual anomaly detection, which allows to\u0000support market surveillance aimed at identifying potential insider trading\u0000activities. This method lies in the reconstruction-based paradigm and employs\u0000principal component analysis and autoencoders as dimensionality reduction\u0000techniques. The only input of this method is the trading position of each\u0000investor active on the asset for which we have a price sensitive event (PSE).\u0000After determining reconstruction errors related to the trading profiles,\u0000several conditions are imposed in order to identify investors whose behavior\u0000could be suspicious of insider trading related to the PSE. As a case study, we\u0000apply our method to investor resolved data of Italian stocks around takeover\u0000bids.","PeriodicalId":501139,"journal":{"name":"arXiv - QuantFin - Statistical Finance","volume":"108 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140034841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"MambaStock: Selective state space model for stock prediction","authors":"Zhuangwei Shi","doi":"arxiv-2402.18959","DOIUrl":"https://doi.org/arxiv-2402.18959","url":null,"abstract":"The stock market plays a pivotal role in economic development, yet its\u0000intricate volatility poses challenges for investors. Consequently, research and\u0000accurate predictions of stock price movements are crucial for mitigating risks.\u0000Traditional time series models fall short in capturing nonlinearity, leading to\u0000unsatisfactory stock predictions. This limitation has spurred the widespread\u0000adoption of neural networks for stock prediction, owing to their robust\u0000nonlinear generalization capabilities. Recently, Mamba, a structured state\u0000space sequence model with a selection mechanism and scan module (S6), has\u0000emerged as a powerful tool in sequence modeling tasks. Leveraging this\u0000framework, this paper proposes a novel Mamba-based model for stock price\u0000prediction, named MambaStock. The proposed MambaStock model effectively mines\u0000historical stock market data to predict future stock prices without handcrafted\u0000features or extensive preprocessing procedures. Empirical studies on several\u0000stocks indicate that the MambaStock model outperforms previous methods,\u0000delivering highly accurate predictions. This enhanced accuracy can assist\u0000investors and institutions in making informed decisions, aiming to maximize\u0000returns while minimizing risks. This work underscores the value of Mamba in\u0000time-series forecasting. Source code is available at\u0000https://github.com/zshicode/MambaStock.","PeriodicalId":501139,"journal":{"name":"arXiv - QuantFin - Statistical Finance","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140010546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Navigating Complexity: Constrained Portfolio Analysis in High Dimensions with Tracking Error and Weight Constraints","authors":"Mehmet Caner, Qingliang Fan, Yingying Li","doi":"arxiv-2402.17523","DOIUrl":"https://doi.org/arxiv-2402.17523","url":null,"abstract":"This paper analyzes the statistical properties of constrained portfolio\u0000formation in a high dimensional portfolio with a large number of assets.\u0000Namely, we consider portfolios with tracking error constraints, portfolios with\u0000tracking error jointly with weight (equality or inequality) restrictions, and\u0000portfolios with only weight restrictions. Tracking error is the portfolio's\u0000performance measured against a benchmark (an index usually), {color{black}{and\u0000weight constraints refers to specific allocation of assets within the\u0000portfolio, which often come in the form of regulatory requirement or fund\u0000prospectus.}} We show how these portfolios can be estimated consistently in\u0000large dimensions, even when the number of assets is larger than the time span\u0000of the portfolio. We also provide rate of convergence results for weights of\u0000the constrained portfolio, risk of the constrained portfolio and the Sharpe\u0000Ratio of the constrained portfolio. To achieve those results we use a new\u0000machine learning technique that merges factor models with nodewise regression\u0000in statistics. Simulation results and empirics show very good performance of\u0000our method.","PeriodicalId":501139,"journal":{"name":"arXiv - QuantFin - Statistical Finance","volume":"53 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140011231","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yifan Duan, Guibin Zhang, Shilong Wang, Xiaojiang Peng, Wang Ziqi, Junyuan Mao, Hao Wu, Xinke Jiang, Kun Wang
{"title":"CaT-GNN: Enhancing Credit Card Fraud Detection via Causal Temporal Graph Neural Networks","authors":"Yifan Duan, Guibin Zhang, Shilong Wang, Xiaojiang Peng, Wang Ziqi, Junyuan Mao, Hao Wu, Xinke Jiang, Kun Wang","doi":"arxiv-2402.14708","DOIUrl":"https://doi.org/arxiv-2402.14708","url":null,"abstract":"Credit card fraud poses a significant threat to the economy. While Graph\u0000Neural Network (GNN)-based fraud detection methods perform well, they often\u0000overlook the causal effect of a node's local structure on predictions. This\u0000paper introduces a novel method for credit card fraud detection, the\u0000textbf{underline{Ca}}usal textbf{underline{T}}emporal\u0000textbf{underline{G}}raph textbf{underline{N}}eural textbf{N}etwork\u0000(CaT-GNN), which leverages causal invariant learning to reveal inherent\u0000correlations within transaction data. By decomposing the problem into discovery\u0000and intervention phases, CaT-GNN identifies causal nodes within the transaction\u0000graph and applies a causal mixup strategy to enhance the model's robustness and\u0000interpretability. CaT-GNN consists of two key components: Causal-Inspector and\u0000Causal-Intervener. The Causal-Inspector utilizes attention weights in the\u0000temporal attention mechanism to identify causal and environment nodes without\u0000introducing additional parameters. Subsequently, the Causal-Intervener performs\u0000a causal mixup enhancement on environment nodes based on the set of nodes.\u0000Evaluated on three datasets, including a private financial dataset and two\u0000public datasets, CaT-GNN demonstrates superior performance over existing\u0000state-of-the-art methods. Our findings highlight the potential of integrating\u0000causal reasoning with graph neural networks to improve fraud detection\u0000capabilities in financial transactions.","PeriodicalId":501139,"journal":{"name":"arXiv - QuantFin - Statistical Finance","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139949644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Steven Y. K. Wong, Jennifer S. K. Chan, Lamiae Azizi
{"title":"Quantifying neural network uncertainty under volatility clustering","authors":"Steven Y. K. Wong, Jennifer S. K. Chan, Lamiae Azizi","doi":"arxiv-2402.14476","DOIUrl":"https://doi.org/arxiv-2402.14476","url":null,"abstract":"Time-series with time-varying variance pose a unique challenge to uncertainty\u0000quantification (UQ) methods. Time-varying variance, such as volatility\u0000clustering as seen in financial time-series, can lead to large mismatch between\u0000predicted uncertainty and forecast error. Building on recent advances in neural\u0000network UQ literature, we extend and simplify Deep Evidential Regression and\u0000Deep Ensembles into a unified framework to deal with UQ under the presence of\u0000volatility clustering. We show that a Scale Mixture Distribution is a simpler\u0000alternative to the Normal-Inverse-Gamma prior that provides favorable\u0000complexity-accuracy trade-off. To illustrate the performance of our proposed\u0000approach, we apply it to two sets of financial time-series exhibiting\u0000volatility clustering: cryptocurrencies and U.S. equities.","PeriodicalId":501139,"journal":{"name":"arXiv - QuantFin - Statistical Finance","volume":"67 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139949666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Applying News and Media Sentiment Analysis for Generating Forex Trading Signals","authors":"Oluwafemi F Olaiyapo","doi":"arxiv-2403.00785","DOIUrl":"https://doi.org/arxiv-2403.00785","url":null,"abstract":"The objective of this research is to examine how sentiment analysis can be\u0000employed to generate trading signals for the Foreign Exchange (Forex) market.\u0000The author assessed sentiment in social media posts and news articles\u0000pertaining to the United States Dollar (USD) using a combination of methods:\u0000lexicon-based analysis and the Naive Bayes machine learning algorithm. The\u0000findings indicate that sentiment analysis proves valuable in forecasting market\u0000movements and devising trading signals. Notably, its effectiveness is\u0000consistent across different market conditions. The author concludes that by\u0000analyzing sentiment expressed in news and social media, traders can glean\u0000insights into prevailing market sentiments towards the USD and other pertinent\u0000countries, thereby aiding trading decision-making. This study underscores the\u0000importance of weaving sentiment analysis into trading strategies as a pivotal\u0000tool for predicting market dynamics.","PeriodicalId":501139,"journal":{"name":"arXiv - QuantFin - Statistical Finance","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140034646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hanshuang Tong, Jun Li, Ning Wu, Ming Gong, Dongmei Zhang, Qi Zhang
{"title":"Ploutos: Towards interpretable stock movement prediction with financial large language model","authors":"Hanshuang Tong, Jun Li, Ning Wu, Ming Gong, Dongmei Zhang, Qi Zhang","doi":"arxiv-2403.00782","DOIUrl":"https://doi.org/arxiv-2403.00782","url":null,"abstract":"Recent advancements in large language models (LLMs) have opened new pathways\u0000for many domains. However, the full potential of LLMs in financial investments\u0000remains largely untapped. There are two main challenges for typical deep\u0000learning-based methods for quantitative finance. First, they struggle to fuse\u0000textual and numerical information flexibly for stock movement prediction.\u0000Second, traditional methods lack clarity and interpretability, which impedes\u0000their application in scenarios where the justification for predictions is\u0000essential. To solve the above challenges, we propose Ploutos, a novel financial\u0000LLM framework that consists of PloutosGen and PloutosGPT. The PloutosGen\u0000contains multiple primary experts that can analyze different modal data, such\u0000as text and numbers, and provide quantitative strategies from different\u0000perspectives. Then PloutosGPT combines their insights and predictions and\u0000generates interpretable rationales. To generate accurate and faithful\u0000rationales, the training strategy of PloutosGPT leverage rearview-mirror\u0000prompting mechanism to guide GPT-4 to generate rationales, and a dynamic token\u0000weighting mechanism to finetune LLM by increasing key tokens weight. Extensive\u0000experiments show our framework outperforms the state-of-the-art methods on both\u0000prediction accuracy and interpretability.","PeriodicalId":501139,"journal":{"name":"arXiv - QuantFin - Statistical Finance","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140034385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"RAGIC: Risk-Aware Generative Adversarial Model for Stock Interval Construction","authors":"Jingyi Gu, Wenlu Du, Guiling Wang","doi":"arxiv-2402.10760","DOIUrl":"https://doi.org/arxiv-2402.10760","url":null,"abstract":"Efforts to predict stock market outcomes have yielded limited success due to\u0000the inherently stochastic nature of the market, influenced by numerous\u0000unpredictable factors. Many existing prediction approaches focus on\u0000single-point predictions, lacking the depth needed for effective\u0000decision-making and often overlooking market risk. To bridge this gap, we\u0000propose a novel model, RAGIC, which introduces sequence generation for stock\u0000interval prediction to quantify uncertainty more effectively. Our approach\u0000leverages a Generative Adversarial Network (GAN) to produce future price\u0000sequences infused with randomness inherent in financial markets. RAGIC's\u0000generator includes a risk module, capturing the risk perception of informed\u0000investors, and a temporal module, accounting for historical price trends and\u0000seasonality. This multi-faceted generator informs the creation of\u0000risk-sensitive intervals through statistical inference, incorporating\u0000horizon-wise insights. The interval's width is carefully adjusted to reflect\u0000market volatility. Importantly, our approach relies solely on publicly\u0000available data and incurs only low computational overhead. RAGIC's evaluation\u0000across globally recognized broad-based indices demonstrates its balanced\u0000performance, offering both accuracy and informativeness. Achieving a consistent\u000095% coverage, RAGIC maintains a narrow interval width. This promising outcome\u0000suggests that our approach effectively addresses the challenges of stock market\u0000prediction while incorporating vital risk considerations.","PeriodicalId":501139,"journal":{"name":"arXiv - QuantFin - Statistical Finance","volume":"23 6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139902514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Towards Financially Inclusive Credit Products Through Financial Time Series Clustering","authors":"Tristan Bester, Benjamin Rosman","doi":"arxiv-2402.11066","DOIUrl":"https://doi.org/arxiv-2402.11066","url":null,"abstract":"Financial inclusion ensures that individuals have access to financial\u0000products and services that meet their needs. As a key contributing factor to\u0000economic growth and investment opportunity, financial inclusion increases\u0000consumer spending and consequently business development. It has been shown that\u0000institutions are more profitable when they provide marginalised social groups\u0000access to financial services. Customer segmentation based on consumer\u0000transaction data is a well-known strategy used to promote financial inclusion.\u0000While the required data is available to modern institutions, the challenge\u0000remains that segment annotations are usually difficult and/or expensive to\u0000obtain. This prevents the usage of time series classification models for\u0000customer segmentation based on domain expert knowledge. As a result, clustering\u0000is an attractive alternative to partition customers into homogeneous groups\u0000based on the spending behaviour encoded within their transaction data. In this\u0000paper, we present a solution to one of the key challenges preventing modern\u0000financial institutions from providing financially inclusive credit, savings and\u0000insurance products: the inability to understand consumer financial behaviour,\u0000and hence risk, without the introduction of restrictive conventional credit\u0000scoring techniques. We present a novel time series clustering algorithm that\u0000allows institutions to understand the financial behaviour of their customers.\u0000This enables unique product offerings to be provided based on the needs of the\u0000customer, without reliance on restrictive credit practices.","PeriodicalId":501139,"journal":{"name":"arXiv - QuantFin - Statistical Finance","volume":"140 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139925578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Emoji Driven Crypto Assets Market Reactions","authors":"Xiaorui Zuo, Yao-Tsung Chen, Wolfgang Karl Härdle","doi":"arxiv-2402.10481","DOIUrl":"https://doi.org/arxiv-2402.10481","url":null,"abstract":"In the burgeoning realm of cryptocurrency, social media platforms like\u0000Twitter have become pivotal in influencing market trends and investor\u0000sentiments. In our study, we leverage GPT-4 and a fine-tuned transformer-based\u0000BERT model for a multimodal sentiment analysis, focusing on the impact of emoji\u0000sentiment on cryptocurrency markets. By translating emojis into quantifiable\u0000sentiment data, we correlate these insights with key market indicators like BTC\u0000Price and the VCRIX index. This approach may be fed into the development of\u0000trading strategies aimed at utilizing social media elements to identify and\u0000forecast market trends. Crucially, our findings suggest that strategies based\u0000on emoji sentiment can facilitate the avoidance of significant market downturns\u0000and contribute to the stabilization of returns. This research underscores the\u0000practical benefits of integrating advanced AI-driven analyses into financial\u0000strategies, offering a nuanced perspective on the interplay between digital\u0000communication and market dynamics in an academic context.","PeriodicalId":501139,"journal":{"name":"arXiv - QuantFin - Statistical Finance","volume":"147 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139904116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}