Ersan, Oğuz

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Ersan, OĞUZ
ERSAN, Oğuz
Ersan, O.
O. Ersan
E., Oğuz
Oğuz ERSAN
Ersan, Oğuz
Ersan,Oguz
Ersan O.
E., Oguz
Oğuz Ersan
Oguz, Ersan
Ersan, Oguz
OĞUZ ERSAN
Ersan,O.
E.,Oguz
ERSAN, OĞUZ
Oğuz, Abdullah Ersan
Ersan, Oğuz
Job Title
Doç. Dr.
Email Address
oguzersan@khas.edu.tr
Scopus Author ID
Turkish CoHE Profile ID
Google Scholar ID
WoS Researcher ID
Scholarly Output

20

Articles

16

Citation Count

158

Supervised Theses

2

Scholarly Output Search Results

Now showing 1 - 10 of 19
  • Article
    Impact of the Covid-19 Market Turmoil on Investor Behavior: a Panel Var Study of Bank Stocks in Borsa Istanbul
    (Mdpi, 2024) Ekinci, Cumhur; Ersan, Oğuz; Ersan, Oguz
    Assuming that investors can be foreign or local, do high-frequency trading (HFT) or not, and submit orders through a bank-owned or non-bank-owned broker, we associated trades to various investors. Then, building a panel vector autoregressive model, we analyzed the dynamic relation of these investors with returns and among each other before and during the COVID-19 market crash. Results show that investor groups have influence on each other. Their net purchases also interact with returns. Moreover, during the turmoil caused by the pandemic, except foreign investors not involved in HFT, the response of any investor group (retail/institutional, domestic investors doing HFT and those not doing HFT, and foreign investors doing HFT) significantly altered. This shows that the interrelation among investor groups is dynamic and sensitive to market conditions.
  • Article
    Where do tourism tokens travel to and from?
    (Routledge Journals, Taylor & Francis Ltd, 2023) Ersan, Oğuz; Demir, Ender; Ersan, Oguz
    This study aims to identify the sources of spillovers affecting tourism tokens and classify the type of assets to which they correspond. Using daily data for different asset classes from June 2018 through November 2022, we employ a TVP-VAR methodology to test the connectedness between two tourism tokens, two leading travel equity indices, and the two dominant cryptocurrencies, namely, Bitcoin and Ethereum. The findings show that tourism tokens are relatively independent of fluctuations in the traditional sources affecting the travel and leisure sector, such as the U.S. dollar, the price of oil, or travel equity indices. These results hint that tourism tokens are more closely related to cryptocurrencies rather than pure travel goods. The results may help decision-makers in the travel and hospitality industries considering the use of tourism tokens identify the potential forces impacting them.
  • Article
    Daily and Intraday Herding Within Different Types of Investors in Borsa Istanbul
    (Routledge Journals, Taylor & Francis Ltd, 2019) Dalgıç, Nihan; Ersan, Oğuz; Ekinci, Cumhur; Ersan, Oğuz
    This paper aims to explore the daily and intraday herd behavior of various investor groups trading in an emerging equity market, Borsa Istanbul (BIST). We analyze a one-year tick-by-tick order and trade data of BIST 100 Index stocks and document differences in herding behavior of investor groups considering market capitalization, market conditions, and announcements as well as daily and intraday periodicities. We find that nonprofessional investors (brokerage houses and domestic funds) tend to herd on large (small) stocks; their herding behavior mostly exhibits a U shape (an inverse U shape) during the day. All types of investors tend to herd in down markets on a daily basis while this behavior disappears, even inverts intraday.
  • Article
    Detecting and date-stamping bubbles in fan tokens
    (Elsevier, 2024) Ersan, Oğuz; Demir, Ender; Ersan, Oguz
    We focus on the existence of bubbles in fan tokens, utilizing the Supremum Augmented DickeyFuller (SADF) and Generalized Supremum Augmented Dickey -Fuller (GSADF) tests. We use daily closing prices of the top 20 fan tokens according to their market capitalization, along with Bitcoin, Ethereum, and Chiliz. The evidence from the GSADF test results indicates that the prices of 13 out of 20 fan tokens and the three cryptocurrencies have explosive periods associated with bubbles. Our results also show that the percentage of bubble days is between 0 % and 5% for all fan tokens. Among the 13 fan tokens exhibiting bubble behavior in their prices, nine have multiple sub -periods associated with bubbles, while only four tokens have a single sub -period with explosive prices. Bubbles in token prices are short-lived bubbles; most last for a few days. As a robustness analysis, we also perform LPPLS (Log -Periodic Power Law Singularity), providing similar results. Further analysis shows that trading volume, fan token return, Economic Policy Uncertainty (EPU), Daily Infectious Disease Equity Market Volatility (EMVID) are positively associated with the presence of bubbles in fan token prices, while oil return is negatively associated with bubbles.
  • Article
    Pinstimation: an R Package for Estimating Probability of Informed Trading Models
    (Technische Universitaet Wien, 2023) Ghachem,M.; Ersan, Oğuz; Ersan,O.
    The purpose of this paper is to introduce the R package PINstimation. The package is designed for fast and accurate estimation of the probability of informed trading models through the implementation of well-established estimation methods. The models covered are the original PIN model (Easley and O’Hara 1992; Easley et al. 1996), the multilayer PIN model (Ersan 2016), the adjusted PIN model (Duarte and Young 2009), and the volume-synchronized PIN (Easley, De Prado, and O’Hara 2011; Easley, López De Prado, and O’Hara 2012). These core functionalities of the package are supplemented with utilities for data simulation, aggregation and classification tools. In addition to a detailed overview of the package functions, we provide a brief theoretical review of the main methods implemented in the package. Further, we provide examples of use of the package on trade-level data for 58 Swedish stocks, and report straightforward, comparative and intriguing findings on informed trading. These examples aim to highlight the capabilities of the package in tackling relevant research questions and illustrate the wide usage possibilities of PINstimation for both academics and practitioners. © (2023), (Technische Universitaet Wien). All Rights Reserved.
  • Article
    Connectedness Among Fan Tokens and Stocks of Football Clubs
    (Elsevier, 2022) Ersan, Oguz; Ersan, Oğuz; Demir, Ender; Assaf, Ata
    This paper examines the dynamic connectedness among the fan tokens and their corresponding stocks using the TVP-VAR approach. We use daily data from December 11, 2020, to January 31, 2022, for the Juventus FC, AS Roma, Galatasaray, and Trabzonspor tokens and stocks. Our results indicate that shocks transmitted to any token are larger than the ones to the stocks, with the tokens being the net transmitters of shocks to both the tokens and stocks. Then, our results indicate that the two asset classes are considered independent of each other, with the total connectedness decreasing over time, and indicating that less than 10% of the contributions in any token (stock) is from the stocks (remaining stocks). This implies that the idiosyncratic contri-butions to the variations in the utilized group of assets are considerably low when compared to the system contributions. Finally, we provide some implications for investment and portfolio management.
  • Article
    Are Fan Tokens Fan Tokens?
    (Academic Press Inc Elsevier Science, 2022) Ersan, Oğuz; Ersan, Oguz; Popesko, Boris
    Fan tokens, digital assets providing privileges including rewards and promotions as well as voting rights in polls, recently became highly popular among the football clubs and the (fan) investors. Fan tokens differ from the stocks of football clubs with respect to ownership properties. Fan tokens might be associated with investor mood changes and reaction to match results. This paper aims to explore the impact of football match results on token prices of the clubs. We show that both the losses and wins in the most prestigious European tournament, UEFA Champions League affect the fan token abnormal returns, losses with an effect of a larger magnitude. Domestic matches and Europa League matches are not followed by similar reactions from the investors. Our results are robust to the use of alternative model specifications and various benchmark assets.
  • Article
    What Drives the Return and Volatility Spillover Between Defis and Cryptocurrencies?
    (Wiley, 2024) Assaf, Ata; Ersan, Oğuz; Demir, Ender; Ersan, Oguz
    In this paper, we study the return and volatility connectedness between cryptocurrencies and DeFi Tokens, considering the impact of different uncertainty indices on their connectivity. Initially, we estimate a TVP-VAR model to obtain the total connectedness between the two markets. We find that returns on the cryptocurrencies transmit significantly larger shocks and, thus, are responsible for most variations in the majority of DeFis' returns. Then, to analyse the impact of uncertainty on total return and volatility connectedness, we use four factors, namely, Economic Policy Uncertainty (EPU), The Chicago Board Options Exchange Volatility Index (VIX), Infectious Disease Equity Market Volatility Tracker (ID-EMV) and Geopolitical Risks (GPR). We find that except for geopolitical risks, all three measures have a positive impact on return and volatility connectedness, while GPR exerts a negative impact. Finally, we provide implications for researchers, market participants and policymakers.
  • Article
    Identifying Information Types in the Estimation of Informed Trading: an Improved Algorithm
    (Multidisciplinary Digital Publishing Institute (MDPI), 2024) Ersan,O.; Ersan, Oğuz; Ghachem,M.
    The growing frequency of news arrivals, partly fueled by the proliferation of data sources, has made the assumptions of the classical probability of informed trading (PIN) model outdated. In particular, the model’s assumption of a single type of information event no longer reflects the complexity of modern financial markets, making the accurate detection of information types (layers) crucial for estimating the probability of informed trading. We propose a layer detection algorithm to accurately find the number of distinct information types within a dataset. It identifies the number of information layers by clustering order imbalances and examining their homogeneity using properly constructed confidence intervals for the Skellam distribution. We show that our algorithm manages to find the number of information layers with very high accuracy both when uninformed buyer and seller intensities are equal and when they differ from each other (i.e., between 86% and 95% accuracy rates). We work with more than 500,000 simulations of quarterly datasets with various characteristics and make a large set of robustness checks. © 2024 by the authors.
  • Article
    The Speed of Stock Price Adjustment To Corporate Announcements: Insights From Turkey
    (Elsevier, 2020) Ersan, Oğuz; Ersan, Oğuz; Şimşir, Serif Aziz; Şimsek, Koray D.; Afan, Hasan
    The market reaction speeds to the news flow are currently measured at the millisecond level in developed markets. We investigate, using a unique setting from Turkey, whether the market reaction speeds in less sophisticated markets are on par with those of developed markets. We find that market reaction times to corporate announcements are slower than documented in recent studies, although markets react to positive news more quickly than negative news. When high-frequency traders are more active in the market prior to announcements, the speed of price adjustment is slower. Finally, we find sizable profit opportunities for investors following event-driven strategies.