Cam, Handan; Demirel, Ugur

The airline industry significantly promotes cultural, social, and financial globalization by facilitating connections between nations and individuals. Airline finance encompasses the intricate aspects of managing the economic, operational, and strategic elements of airline corporations on a global scale. In this industry, it is necessary to address various factors, including revenue management, risk management, cost control, and market competition. The interaction of these factors in the global aviation sector influences the financial situation of airlines, requiring strategic planning, flexibility, and a complete understanding of market dynamics. Sentiment analysis in aviation finance uses text and data mining techniques to examine emotional elements derived from social networks, consumer feedback, and news. This facilitates understanding consumer preferences, new trends, investment opportunities, risks, and marketing strategies. Sentiment analysis also helps manage brand reputation by monitoring sentiments expressed by passengers and the general public, allowing proactive measures to maintain a positive reputation. Airline companies rely on conventional customer feedback forms, which can be extremely laborious and timeconsuming. Twitter data is valuable for collecting consumer feedback tweets and conducting sentiment analysis. In this paper, we work on a dataset comprising tweets from the top major US airlines and perform a sentiment analysis in airline finance that can be used more efficiently and effectively in decision-making processes. This would allow airlines to adopt a more knowledgeable, targeted, and competitive strategy by understanding and assessing emotional context.

Cam, Handan; Cam, Alper Veli; Demirel, Ugur; Ahmed, Sana

This paper presents a sentiment analysis combining the lexicon-based and machine learning (ML)-based approaches in Turkish to investigate the public mood for the prediction of stock market behavior in BIST30, Borsa Istanbul. Our main motivation behind this study is to apply sentiment analysis to financial-related tweets in Turkish. We import 17189 tweets posted as "#Borsaistanbul, #Bist, #Bist30, #Bist100″ on Twitter between November 7, 2022, and November 15, 2022, via a MAXQDA 2020, a qualitative data analysis program. For the lexicon-based side, we use a multilingual sentiment offered by the Orange program to label the polarities of the 17189 samples as positive, negative, and neutral labels. Neutral labels are discarded for the machine learning experiments. For the machine learning side, we select 9076 data as positive and negative to implement the classification problem with six different supervised machine learning classifiers conducted in Python 3.6 with the sklearn library. In experiments, 80 % of the selected data is used for the training phase and the rest is used for the testing and validation phase. Results of the experiments show that the Support Vector Machine and Multilayer Perceptron classifier perform better than other classifiers with 0.89 and 0.88 accuracy and AUC values of 0.8729 and 0.8647 respectively. Other classifiers obtain approximately a 78,5 % accuracy rate. It is possible to increase sentiment analysis accuracy with parameter optimization on a larger, cleaner, and more balanced dataset by changing the pre-processing steps. This work can be expanded in the future to develop better sentiment analysis using deep learning approaches.

Demirel, Ugur; Cam, Handan; Unlu, Ramazan

Stock market prediction in financial and commodity markets is a major challenge for speculators, investors, and companies but also profitable with an accurate prediction. Thus, obtaining accurate prediction results becomes extremely important especially while the stock market is essentially volatile, nonlinear, complicated, adaptive, nonparametric and unpredictable in nature. This study aims to forecast the opening and closing stock prices of 42 firms listed in Istanbul Stock Exchange National 100 Index (ISE-100) using well-known machine learning methods, Multilayer Perceptrons (MLP) and Support Vector Machines (SVM) models and deep learning algorithm, Long Short Term Memory (LSTM) by comparing their forecasting performances. The analysis includes 9 years of data from 01.01.2010 to 01.01.2019. For each firm 2249 data for the opening and 2249 for the closing stock prices were established as daily data sets. Forecasting performance of these methods was evaluated by applying different criteria for each model: root mean squared error (RMSE), mean squared error (MSE) and R-squared (R2). The results of this study show that MLP and LSTM models become advantageous in estimating the opening and closing stock prices comparing to SVM model.