Andrés García-Medina

Dr. Andrés García-Medina

Centro de Investigación en Matemáticas
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Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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14 March 2023 in Computational Economics
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Andrés García-MedinaAndrés García-Medina
Andrés García-Medina
EAEster Aguayo-Moreno
Ester Aguayo-Moreno

11 July 2020 in Entropy
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Andrés García-MedinaAndrés García-Medina
Andrés García-Medina
JCJosé B Hernández C
José B Hernández C
We investigate the effects of the recent financial turbulence of 2020 on the market of cryptocurrencies taking into account the hourly price and volume of transactions from December 2019 to April 2020. The data were subdivided into time frames and analyzed the directed network generated by the estimation of the multivariate transfer entropy. The approach followed here is based on a greedy algorithm and multiple hypothesis testing. Then, we explored the clustering coefficient and the degree distributions of nodes for each subperiod. It is found the clustering coefficient increases dramatically in March and coincides with the most severe fall of the recent worldwide stock markets crash. Further, the log-likelihood in all cases bent over a power law distribution, with a higher estimated power during the period of major financial contraction. Our results suggest the financial turbulence induce a higher flow of information on the cryptocurrency market in the sense of a higher clustering coefficient and complexity of the network. Hence, the complex properties of the multivariate transfer entropy network may provide early warning signals of increasing systematic risk in turbulence times of the cryptocurrency markets.

2 January 2020 in PLOS ONE
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Andrés García-MedinaAndrés García-Medina
Andrés García-Medina
GFGraciela González Farías
Graciela González Farías
We determine the number of statistically significant factors in a high dimensional predictive model of cryptocurrencies using a random matrix test. The applied predictive model is of the reduced rank regression (RRR) type; in particular, we choose a flavor that can be regarded as canonical correlation analysis (CCA). A variable selection of hourly cryptocurrencies is performed using the Symbolic estimation of Transfer Entropy (STE) measure from information theory. In simulated studies, STE shows better performance compared to the Granger causality approach when considering a nonlinear system and a linear system with many drivers. In the application to cryptocurrencies, the directed graph associated to the variable selection shows a robust pattern of predictor and response clusters, where the community detection was contrasted with the modularity approach. Also, the centralities of the network discriminate between the two main types of cryptocurrencies, i.e., coins and tokens. On the factor determination of the predictive model, the result supports retaining more factors contrary to the usual visual inspection, with the additional advantage that the subjective element is avoided. In particular, it is observed that the dynamic behavior of the number of factors is moderately anticorrelated with the dynamics of the constructed composite index of predictor and response cryptocurrencies. This finding opens up new insights for anticipating possible declines in cryptocurrency prices on exchanges. Furthermore, our study suggests the existence of specific-predictor and specific-response factors, where only a small number of currencies are predominant.

26 November 2021 in Entropy
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Andrés García-MedinaAndrés García-Medina
Andrés García-Medina
Toan Luu Duc HuynhToan Luu Duc Huynh
Toan Luu Duc Huynh
Bitcoin has attracted attention from different market participants due to unpredictable price patterns. Sometimes, the price has exhibited big jumps. Bitcoin prices have also had extreme, unexpected crashes. We test the predictive power of a wide range of determinants on bitcoins’ price direction under the continuous transfer entropy approach as a feature selection criterion. Accordingly, the statistically significant assets in the sense of permutation test on the nearest neighbour estimation of local transfer entropy are used as features or explanatory variables in a deep learning classification model to predict the price direction of bitcoin. The proposed variable selection do not find significative the explanatory power of NASDAQ and Tesla. Under different scenarios and metrics, the best results are obtained using the significant drivers during the pandemic as validation. In the test, the accuracy increased in the post-pandemic scenario of July 2020 to January 2021 without drivers. In other words, our results indicate that in times of high volatility, Bitcoin seems to self-regulate and does not need additional drivers to improve the accuracy of the price direction.

1 July 2018 in Physica A: Statistical Mechanics and its Applications
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Andrés García-MedinaAndrés García-Medina
Andrés García-Medina
LSLeonidas Sandoval
Leonidas Sandoval
EBEfraín Urrutia Bañuelos
Efraín Urrutia Bañuelos
AMA.M. Martínez-Argüello
A.M. Martínez-Argüello

27 March 2023 in Finance Research Letters
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LML. Molero-González
L. Molero-González
Juan E. Trinidad SegoviaJuan E. Trinidad Segovia
Juan E. Trinidad Segovia
M.A. Sánchez-GraneroM.A. Sánchez-Granero
M.A. Sánchez-Granero
Andrés García-MedinaAndrés García-Medina
Andrés García-Medina