Raquel Gaspar

Dr. Raquel Gaspar

ISEG-UL – Universidade de Lisboa, REM-CEMAPRE – Research in Economics and Mathematics
orcid

Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

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

Representative Publications

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2 July 2020 in Risks
Verified
Journal Article
Open access
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Raquel GasparRaquel Gaspar
Raquel Gaspar
SLSara D. Lopes
Sara D. Lopes
BSBernardo Sequeira
Bernardo Sequeira
In this study, we use Neural Networks (NNs) to price American put options. We propose two NN models—a simple one and a more complex one—and we discuss the performance of two NN models with the Least-Squares Monte Carlo (LSM) method. This study relies on American put option market prices, for four large U.S. companies—Procter and Gamble Company (PG), Coca-Cola Company (KO), General Motors (GM), and Bank of America Corp (BAC). Our dataset is composed of all options traded within the period December 2018 until March 2019. Although on average, both NN models perform better than LSM, the simpler model (NN Model 1) performs quite close to LSM. Moreover, the second NN model substantially outperforms the other models, having an RMSE ca. 40% lower than the presented by LSM. The lower RMSE is consistent across all companies, strike levels, and maturities. In summary, all methods present a good accuracy; however, after calibration, NNs produce better results in terms of both execution time and Root Mean Squared Error (RMSE).

1 February 2012 in Communications in Statistics - Simulation and Computation
Verified
Journal Article
Open access
JSJ. Beleza Sousa
J. Beleza Sousa
MEManuel Leote Esquivel
Manuel Leote Esquivel
Raquel GasparRaquel Gaspar
Raquel Gaspar
In this article, we calibrate the Vasicek interest rate model under the risk neutral measure by learning the model parameters using Gaussian processes for machine learning regression. The calibration is done by maximizing the likelihood of zero coupon bond log prices, using mean and covariance functions computed analytically, as well as likelihood derivatives with respect to the parameters. The maximization method used is the conjugate gradients. The only prices needed for calibration are zero coupon bond prices and the parameters are directly obtained in the arbitrage free risk neutral measure.

3 February 2024 in FinTech
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Journal Article
Open access
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Raquel GasparRaquel Gaspar
Raquel Gaspar
MOMadalena Oliveira
Madalena Oliveira
The rise of digital technology and artificial intelligence has led to a significant change in the way financial services are delivered. One such development is the emergence of robo advising, which is an automated investment advisory service that utilizes algorithms to provide investment advice and portfolio management to investors. Robo advisors gather information about clients’ preferences, financial situations, and future goals through questionnaires. Subsequently, they recommend ETF-based portfolios tailored to match the investor’s risk profile. However, these questionnaires often appear vague, and robo advisors seldom disclose the methodologies employed for investor profiling or asset allocation. This study aims to contribute by introducing an investor profiling method relying solely on investors’ relative risk aversion (RRA), which, in addition, allows for the determination of optimal allocations. We also show that, for the period under analysis and using the same ETF universe, our RRA portfolios consistently outperform those recommended by the Riskalyze platform, which may suffer from ultraconservadorism in terms of the proposed volatility.

1 January 2004 in SSRN Electronic Journal
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Raquel GasparRaquel Gaspar
Raquel Gaspar
For finite dimensional factor models, the paper studies general quadratic term structures. These term structures include as special cases the affine term struct

1 January 2012 in International Journal of Forecasting
Verified
Journal Article
Closed access
Raquel GasparRaquel Gaspar
Raquel Gaspar

1 June 2008 in Journal of Credit Risk
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Journal Article
Closed access
Raquel GasparRaquel Gaspar
Raquel Gaspar
ISIrina Slinko
Irina Slinko