9 results on '"Helder Rojas"'
Search Results
2. Order Book Dynamics with Liquidity Fluctuations: Asymptotic Analysis of Highly Competitive Regime
- Author
-
Helder Rojas, Artem Logachov, and Anatoly Yambartsev
- Subjects
limit order book ,liquidity fluctuations ,Markov process ,large deviations ,flash crash ,Mathematics ,QA1-939 - Abstract
We introduce a class of Markov models to describe the bid–ask price dynamics in the presence of liquidity fluctuations. In a highly competitive regime, the spread evolution belongs to a class of Markov processes known as a population process with uniform catastrophes. Our mathematical analysis focuses on establishing the law of large numbers, the central limit theorem, and large deviations for this catastrophe-based model. Large deviation theory allows us to illustrate how huge deviations in the spread and prices can occur in the model. Moreover, our research highlights how these local trends and volatility are influenced by the typical values of the bid–ask spread. We calibrated the model parameters using available high-frequency data and conducted Monte Carlo numerical simulations to demonstrate its ability to reasonably replicate key phenomena in the presence of liquidity fluctuations.
- Published
- 2023
- Full Text
- View/download PDF
3. Order Book Dynamics with Liquidity Fluctuations: Limit Theorems and Large Deviations
- Author
-
Anatoly Yambartsev, Helder Rojas, and Artem Logachov
- Subjects
Flash crash ,Quantitative Finance - Trading and Market Microstructure ,Markov chain ,Dynamics (mechanics) ,Mathematical Finance (q-fin.MF) ,algebra_number_theory ,Trading and Market Microstructure (q-fin.TR) ,Market liquidity ,FOS: Economics and business ,Quantitative Finance - Mathematical Finance ,Order book ,Large deviations theory ,Statistical physics ,Limit (mathematics) ,Mathematics - Abstract
We propose a class of stochastic models for a dynamics of limit order book with different type of liquidities. Within this class of models we study the one where a spread decreases uniformly, belonging to the class of processes known as a population processes with uniform catastrophes. The law of large numbers (LLN), central limit theorem (CLT) and large deviations (LD) are proved for our model with uniform catastrophes. Our results allow us to satisfactorily explain the volatility and local trends in the prices, relevant empirical characteristics that are observed in this type of markets. Furthermore, it shows us how these local trends and volatility are determined by the typical values of the bid-ask spread. In addition, we use our model to show how large deviations occur in the spread and prices, such as those observed in flash crashes.
- Published
- 2021
4. Transmission of macroeconomic shocks to risk parameters: Their uses in stress testing
- Author
-
Helder Rojas and David Dias
- Subjects
FOS: Computer and information sciences ,Computer science ,Process (engineering) ,media_common.quotation_subject ,Bayesian probability ,Econometrics (econ.EM) ,0211 other engineering and technologies ,02 engineering and technology ,Management Science and Operations Research ,Stress testing (software) ,Statistics - Applications ,01 natural sciences ,Transfer function ,FOS: Economics and business ,010104 statistics & probability ,Econometrics ,Applications (stat.AP) ,0101 mathematics ,Economics - Econometrics ,media_common ,021103 operations research ,Other Statistics (stat.OT) ,General Business, Management and Accounting ,Statistics - Other Statistics ,Transmission (telecommunications) ,Modeling and Simulation ,Portfolio ,Psychological resilience ,Credit risk - Abstract
In this paper, we are interested in evaluating the resilience of financial portfolios under extreme economic conditions. Therefore, we use empirical measures to characterize the transmission process of macroeconomic shocks to risk parameters. We propose the use of an extensive family of models, called General Transfer Function Models, which condense well the characteristics of the transmission described by the impact measures. The procedure for estimating the parameters of these models is described employing the Bayesian approach and using the prior information provided by the impact measures. In addition, we illustrate the use of the estimated models from the credit risk data of a portfolio.
- Published
- 2019
5. Probabilistic Model for Population Dynamics With Uniform Catastrophes
- Author
-
Helder Rojas and Kevin Fernandez
- Subjects
education.field_of_study ,Law of large numbers ,Stochastic process ,Dynamics (mechanics) ,Population ,Large deviations theory ,Statistical model ,Statistical physics ,Linear growth ,education ,Mathematics ,Central limit theorem - Abstract
In the paper we study the stochastic process which corresponds to the random population dynamics with linear growth and uniform catastrophes, where an eliminating portion of the population is chosen uniformly. The law of large numbers (LLN), central limit theorem (CLT) and large deviations (LD) are proved for our model with uniform catastrophes.
- Published
- 2021
6. Order Book Dynamics in the Presence of Liquidity Fluctuations
- Author
-
Helder Rojas, Artem Logachov, and Anatoly Yambartsev
- Subjects
education.field_of_study ,Stochastic modelling ,Law of large numbers ,Population ,Order book ,Large deviations theory ,Limit (mathematics) ,Statistical physics ,Volatility (finance) ,education ,Mathematics ,Central limit theorem - Abstract
We propose a class of stochastic models for a dynamics of limit order book with different type of liquidities. Within this class of models we study the one where a spread decreases uniformly, belonging to the class of processes known as a population processes with uniform catastrophes. The law of large numbers (LLN), central limit theorem (CLT) and large deviations (LD) are proved for our model with uniform catastrophes. Our results allow us to satisfactorily explain the volatility and local trends in the prices, relevant empirical characteristics that are observed in this type of markets. Furthermore, it shows us how these local trends and volatility are determined by the typical values of the bid-ask spread. In addition, we use our model to show how large deviations occur in the spread and prices, such as those observed in flash crashes.
- Published
- 2020
7. Transfer of macroeconomic shocks in stress tests modeling
- Author
-
Helder Rojas and David Pires Dias
- Subjects
Statistics and Probability ,Computer science ,Process (engineering) ,MACROECONOMIA ,Bayesian probability ,Condensed Matter Physics ,01 natural sciences ,Transfer function ,010305 fluids & plasmas ,Transmission (telecommunications) ,Transfer (computing) ,0103 physical sciences ,Econometrics ,Portfolio ,010306 general physics ,Credit risk - Abstract
In this paper, we are interested in evaluating the resilience of financial portfolios under extreme economic conditions. Therefore, we use empirical measures to characterize the transmission process of macroeconomic shocks to risk parameters. We propose the use of an extensive family of models, called General Transfer Function Models, which condense well the characteristics of the transmission described by the impact measures. The procedure for estimating the parameters of these models is described employing the Bayesian approach and using the prior information provided by the impact measures. In addition, we illustrate the use of the estimated models from the credit risk data of a portfolio.
- Published
- 2021
8. Stress Testing Network Reconstruction via Graphical Causal Model
- Author
-
Helder Rojas and David Dias
- Subjects
FOS: Computer and information sciences ,Mathematical optimization ,Computer science ,0211 other engineering and technologies ,Econometrics (econ.EM) ,02 engineering and technology ,Management Science and Operations Research ,Causal structure ,Stress testing (software) ,01 natural sciences ,Statistics - Applications ,Statistics - Computation ,FOS: Economics and business ,010104 statistics & probability ,FOS: Mathematics ,Applications (stat.AP) ,Graphical model ,0101 mathematics ,Mathematics - Optimization and Control ,Computation (stat.CO) ,Causal model ,Economics - Econometrics ,Structure (mathematical logic) ,021103 operations research ,General Business, Management and Accounting ,Causality ,Optimization and Control (math.OC) ,Modeling and Simulation ,Portfolio ,Credit risk - Abstract
An resilience optimal evaluation of financial portfolios implies having plausible hypotheses about the multiple interconnections between the macroeconomic variables and the risk parameters. In this paper, we propose a graphical model for the reconstruction of the causal structure that links the multiple macroeconomic variables and the assessed risk parameters, it is this structure that we call Stress Testing Network (STN). In this model, the relationships between the macroeconomic variables and the risk parameter define a "relational graph" among their time-series, where related time-series are connected by an edge. Our proposal is based on the temporal causal models, but unlike, we incorporate specific conditions in the structure which correspond to intrinsic characteristics this type of networks. Using the proposed model and given the high-dimensional nature of the problem, we used regularization methods to efficiently detect causality in the time-series and reconstruct the underlying causal structure. In addition, we illustrate the use of model in credit risk data of a portfolio. Finally, we discuss its uses and practical benefits in stress testing., Comment: arXiv admin note: text overlap with arXiv:1809.07401
- Published
- 2019
- Full Text
- View/download PDF
9. Transmission of Macroeconomic Shocks to Risk Parameters: Their Uses in Stress Testing
- Author
-
Helder Rojas and David Dias
- Subjects
Transmission (telecommunications) ,Computer science ,Process (engineering) ,media_common.quotation_subject ,Bayesian probability ,Econometrics ,Portfolio ,Psychological resilience ,Stress testing (software) ,Transfer function ,media_common ,Credit risk - Abstract
In this paper, we are interested in evaluating the resilience of financial portfolios under extreme economic conditions. Therefore, we use empirical measures to characterize the transmission process of macroeconomic shocks to risk parameters. We propose the use of an extensive family of models, called General Transfer Function Models, which condense well the characteristics of the transmission described by the impact measures. The procedure for estimating the parameters of these models is described employing the Bayesian approach and using the prior information provided by the impact measures. In addition, we illustrate the use of the estimated models from the credit risk data of a portfolio.
- Published
- 2018
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.