This paper analyses options/warrants price behavior around an ex-dividend day of underlying shares. Both equity options as financial instruments traded on options exchanges, and warrants/certificates as OTC financial instruments are analyzed. First, the paper analyzes the ex-dividend day share price drop. Findings of this part are further used to analyze the impact of unexpected share price decline on options prices. Further, the paper focuses on volumes of traded options contracts and changes in options prices around the ex-dividend day. The paper focuses on European shares and related options and warrants. The options data was collected from the options exchange EUREX and also from several OTC sources -- Vontobel, Lang & Schwarz, Erste, and xMarkets by Deutsche Börse. The main aim of the paper is to identify market inefficiencies in trading in and valuation of equity options. There are two main conclusions that around the ex-dividend day there is a significantly increased trading activity and the call options depreciate whereas put options appreciate between the cum-dividend and the ex-dividend day. This shows insufficient implementation of the share price drops into options valuation models of options dealers or investors / speculators. Further an impact of unexpected share price behavior was analyzed but no particular pattern has been identified. The impact of the unexpected share price drop (either too high or too low) has ambiguous implications on the options prices. Finally, ways how to utilize on knowledge of inefficient trading in options around the ex-dividend day were suggested. The suggestions were done both from the perspective of an investor / speculator and of an options dealer.

Bakgrund: En fungerande kapitalmarknad är en förutsättning för en nations innovation,vilket i sin tur är fundamentalt för att uppnå ekonomisk tillväxt. Därav blir förståelsen för hurkapitalmarknaden fungerar av största vikt. En av de vanligaste frågorna investerare ochforskare ställer sig är huruvida marknader är effektiva? Kan investerare utgå ifrån attkapitalmarknaden är effektiv och att alla handlar på samma information? Frågan är viktigeftersom kapitalmarknaden är uppbyggd på ett förtroende hos allmänheten, om dettaförtroende raseras kan det få förödande konsekvenser för nationen, utifrån svårigheter medkapitalallokeringen. Denna studie undersöker, med utgångspunkt från effektiva marknader,fenomenet kallat ex-dagseffekten. Finns det prisavvikelser på marknaden och iförekommande fall, finns det en förklaring till detta? Utifrån det undersöker studien specifiktmikrostrukturen som förklaring till den potentiella prisavvikelsen. Syfte: Syftet med studien är att undersöka, analysera, samt förklara förekomsten av exdagseffektenoch dess relation med mikrostrukturen på OMX Stockholm Large Cap,respektive Mid Cap och Small Cap. Metod: Utifrån studiens behov att sammanställa en större mängd data har en kvantitativforskningsstrategi använts. Studiens sekundärdata är insamlad för utdelande bolag noteradepå OMX Stockholm Large, Mid samt Small Cap mellan årtalen 2016 och 2019. Insamladdata har sedan sammanställts till paneldata, vilken ligger till grund för studiens t-test samtmultipla regressioner. Slutsats: Utifrån studiens t-test påvisas att ex-dagseffekten föreligger på studiens utvaldamarknad. Vidare, utifrån studiens regressioner utläses det att mikrostrukturen har en negativpåverkan på PDR. Då förekomst av mikrostrukturen påvisas kan studien inte uttala sig omhuruvida marknaden som undersökts är ineffektiv eller ej. / Background: A functioning capital market is a prerequisite for the innovation of a nation,which in turn is fundamental to achieve economic growth. Hence, the understanding of howthe capital market operates becomes of paramount importance. One of the most commonquestions investors and researchers ask themselves is whether markets are efficient? Caninvestors assume that the capital market is efficient and that everyone trades on the sameinformation? The question is important because the capital market is built upon publicconfidence, and if this trust is destroyed, it can have devastating consequences for the nation,based on difficulties with capital allocation. This study examines, based on efficient markets,the phenomenon called the ex-day effect. Are there price deviations in the market, and ifapplicable, is there an explanation for this? Based on this, the study specifically examines themicrostructure as an explanation for the potential price deviation. Purpose: The purpose of the study is to investigate, analyze, and explain the existence of theex-day effect and its relationship with the microstructure of OMX Stockholm Large Cap, MidCap and Small Cap. Method: Based on the study's need to compile a larger amount of data, a quantitativeresearch strategy has been used. The study's secondary data is collected for distributingcompanies listed on OMX Stockholm Large, Mid and Small Cap between the years 2016 and2019. Collected data has then been compiled into panel data, which is the basis for the study'st-test and multiple regressions. Conclusion: Based on the study's t-test, it is demonstrated that the ex-day effect is present inthe study's selected market. Furthermore, based on the regressions models the study used, itcan be deducted that the microstructure has an impact of PDR. Since the presence of themicrostructure is detected, the study cannot comment on whether the market examined isinefficient or not.

Chapter 1 Summary of the Dissertation "We are in the golden age of fraud." Jim Chanos, Kynikos Associates, Financial Times 24/07/2020. Beyond the speculations about the consecutive waves of Covid, 2020 will be reminded for one of the most notorious failures of a listed firm, due to a massive accounting fraud: the German payment fintech Wirecard. The firm, with 30 subsidiaries in 26 countries, joined the prestigious DAX index just two years before. The spillovers of the billion-euro fraud range from the arrest of top managers to suspicion of auditors, politicians, and regulatory authorities (BaFin, European Commission, and ESMA), as suggested the Financial Times headline "Why was Frankfurt so blind for so long?"1 Such a failure serves as a reminder of the relevance of financial markets regulation, oversight, and enforcement, in order to protect investors and to encourage compliance with regulations. Research on the relationship between the publication of financial misconducts and financial performance for corporates has continuously grown, as illustrated by the recent in- depth literature reviews undergone by Amiram et al. (2018) and Liu and Yawson (2020). It is fueling regulatory debates on how to enforce more efficiently financial regulations. Some specificities of white-collar crimes must be accounted for...

In an effort to examine role of capital markets' efficiency in transmission of monetary policy, 28 time series of market efficiency development are estimated with use of long-term memory and fractal dimension measures and a panel of 27 inflation targeting countries is constructed to run a random effect regres- sion. The cases of Czech Republic and Austria are thereafter more closely examined with use a vector-autoregressive and threshold vector-autoregressive frameworks on macroeconomic data spanning from 1996:Q3 to 2018:Q4. The evidence obtained through the conducted analyses support the hypothesis, that a more efficiently functioning capital market better contributes to monetary policy pass-through, or conversely, that high transaction costs, barriers to cap- ital market entry, or poor information availability may hinder the effects of central bank's monetary policy. JEL Classification F12, F21, F23, H25, H71, H87 Keywords capital market efficiency, inflation targeting, monetary transmission mechanism Author's e-mail teddy.krejci@gmail.com Supervisor's e-mail LK@fsv.cuni.cz

Från och med årsskiftet 2019/2020 kom Sverige och världen att påverkas av pandemin COVID-19. Det finns ett flertal studier på området om hur tidigare kriser och COVID-19 har påverkat marknaden, men avseende den svenska aktiemarknaden är tidigare studier bristande. Marknadseffektivitet är ett väl undersökt område vid tidigare kriser, däribland effektiva marknadshypotesen och Signaleringsteorin. Ett samband borde enligt nämnda teorier finnas mellan förändringarna i aktiekursen och den information som finns på marknaden. Tidigare studier tyder även på att det vid tidigare kriser, samt vid COVID-19 i andra länder, funnits ett samband mellan bolagens storlek och hur aktiekurserna förändras. I och med de restriktioner som tagits fram har hela aktiemarknaden påverkats av COVID-19, och det bör även ha haft en inverkan på hur olika branscher påverkas, vilket har konstaterats i tidigare studier på andra länder. Syftet med studien är att analysera hur den svenska aktiemarknaden har påverkats av nyheter om COVID-19 genom att studera aktiemarknadens effektivitet, bolagens storlek och dess bransch. Eventstudierna genomförs på tre eventfönster baserade på varsin nyhet med empiriskt underlag som utgörs av aktiekurser för bolag på OMX Stockholm. Marknadens effektivitet testas sedan genom t-test på abnormal avkastning vid samtliga event. Ett eventuellt samband mellan abnormal avkastning och bolagens storlek/bransch undersöks också genom regressionsanalyser. Vi finner att aktiemarknaden har agerat effektivt vid event 1 och 2, aktiemarknaden har då prissatt den information som har publicerats. Bolagens storlek kunde ses ha påverkat förändringen i aktiekurserna under samtliga event, men det var endast under event 1 och 2 som det positivt eftersökta sambandet kunde återfinnas. Ett samband kan i event 2 återfinnas mellan vilken bransch som bolagen tillhör och hur mycket deras aktiekurser sjönk mot vad det borde ha gjort vid nyhetssläppet. Konsument cyklisk var den bransch som hade högst negativ abnormal avkastning under event 2. / The purpose of this study is to analyze how the Swedish stock market has been affected by news about COVID-19 by studying the efficiency of the stock market, the size of companies and its industry. Three different event windows linked to each novelty are examined and the empirical basis consists of share prices for companies on OMX Stockholm. Market efficiency is then tested by t-tests on abnormal returns for all events. A relationship was also sought between abnormal returns and size / industry through a regression model. We find that the market has acted effectively at events 1 and 2 and has then priced the information that has been published. The size of the companies can be seen to have affected the change in share prices in all events, but it was only during events 1 and 2 that the positively sought relationship could be found. In event 2, a relationship can be found between which industry the companies belong to and how much their share prices fell compared to what it should have done (abnormal return) at the news release. The industry consumer discretionary has been the most negatively affected during event 2.

The general focus of my dissertation, which consists of two essays, is on how changes in the financial and economic environment surrounding a firm affect managerial incentives and firm policies regarding investment in physical capital, innovation, equity offerings, and repurchases. The first essay in my dissertation examines how product market competition affects firms' investment decisions. While competition among firms benefits consumers via lower prices, greater product variety, higher product quality, and greater innovation, recent studies provide evidence that competition has been declining in the U.S. economy over the past decade. The evidence shows that American firms' profits are at near-record levels relative to GDP and are persistent. Industries have become more concentrated as a result of mergers and acquisitions, and barriers to entry have risen and the rate of new entry has been declining for decades. Taking these findings at face value, we examine empirically whether companies feel less compelled to invest in physical capital and in research and development because they face fewer threats from rival firms. Using both traditional proxies and recently developed text-based measures of industry concentration, we show that firms operating in competitive industries invest significantly more in both physical capital and research and development relative to their peers in concentrated industries. We also report that the propensity to invest less by managers of monopolistic firms is partially mitigated by superior corporate governance that reduces the agency problem, and by certain product market characteristics such as low pricing power and low product differentiation/entry barriers. However, after accounting for all these mitigating factors, the negative association between industry concentration and investment persists. Our results are robust to including various control variables and exclusion of firms from industries that face significant competition from imports. The results are also robust to controlling for endogeneity caused by missing time-invariant and time-varying industry level factors that could potentially be related to both the level of concentration and investments. Overall, our results are consistent with the notion that firms in competitive industries have a greater incentive to invest and innovate to survive and thrive in a competitive environment relative to the managers of the firms in more concentrated industries whose incentive to invest and innovate is to maintain their monopoly rents. Our findings have obvious policy implications in that investment and hence economic growth is being adversely affected in the current era of increasing industry concentration and declining competition. The second essay in my dissertation investigates whether information contained in equity issues and buybacks is fully incorporated into prices such that the market reaction to subsequent earnings announcements is unrelated to those corporate actions. Korajczyk at al. (1991) argue that firms prefer to issue equity when the market is most informed about the quality of the firm to prevent adverse selection costs associated with new equity issues. This implies that equity issues tend to follow credible information releases contained in earnings announcements. However, analyzing a sample of 19,466 SEO pricing dates between 1970 and 2015 and 15,106 buyback announcements between 1994 and 2015 shows that a considerable number of equity offerings and repurchase announcements take place before the announcement of earnings. About 28% of buybacks and 32% of SEO pricings are made in the three weeks prior to an earnings announcement. Given these statistics, we examine whether these corporate actions provide information about upcoming earnings announcements (earnings predictability) to the extent that new information has not been fully incorporated into prices by market participants. We find evidence of earnings predictability: the market reaction to earnings following buyback announcements is higher by 5.1% than the reaction to earnings following equity issues over the (-1,+30) window when four-factor abnormal returns are used; the difference is 2.2% when unadjusted returns are considered. The results are robust to several alternate sample construction methodologies. There are at least two puzzling effects of earnings predictability that are difficult to reconcile with the market efficiency hypothesis. First, there is an incomplete adjustment to SEO pricings and buyback announcements that results in residual market reaction to earnings announcements. Second, prices continue to drift after earnings announcements: upward for buybacks and downward for SEO pricings. Unlike post-earnings announcement drift, the drift documented here does not depend on the market reaction to earnings announcement. We test several reasons for this anomalous behavior including prior returns, price, size of buyback or SEO, analyst forecast errors, and bid-ask spread. We find that information asymmetry proxies partially explain the persistence of earnings predictability following SEO pricings and buyback announcements. / Ph. D. / It is well documented that corporate investments in research and development (R&D) and physical capital are important drivers of economic growth and higher standards of living. Recent articles published by academic community and popular press have provided evidence that the overall competition among U.S. firms has declined. The evidence shows that concentration has increased in 75% of the US industries, the economy has lost about 50% of its publicly traded firms, and the rate of new-business formation has fallen. Given the documented association between corporate investments and economic growth & social welfare, a natural question arising would be whether declining competition is detrimental to investment in both physical capital and R&D. The first chapter of my dissertation aims to answer this question by examining whether companies feel less compelled to invest in physical capital and in R&D because they face fewer threats from rival firms. Our findings show that firms operating in concentrated industries invest significantly less in both physical capital and research and development relative to their peers in competitive industries, consistent with the notion that firms in competitive industries have a greater incentive to invest and innovate to survive and thrive in a competitive environment relative to the managers of the firms in more concentrated industries whose incentive to invest and innovate is to maintain their monopoly rents. Our findings have obvious policy implications in that investment and hence economic growth is being adversely affected in the current era of increasing industry concentration and declining competition. The wealth of the shareholders of publicly traded firms is tied to managers’ decisions about corporate actions such as equity offerings, buybacks, dividends, and mergers as these actions can potentially affect the stock prices and the value of shareholders’ portfolios. The second part of my dissertation investigates whether buybacks or equity offerings announced within a few weeks prior to earnings provide information about upcoming earnings announcements to the extent that new information has not been fully incorporated into prices by market participants. We find that earnings coming after equity offerings are likely to contain bad news and earnings coming after buybacks are likely to contain good news. This implies that buying the shares of the companies that announce a buyback before their earnings and short selling the shares of the companies that issue equity before their earnings will yield a significant return for the investors.

With the surge of Internet-based corporate communication, organization, andinformation management, financial markets have undergone radical transformation. Inthe interconnected economy of today, market participants are forced to acceptcyberattacks, data breaches, system failures, or security flaws as any other (varying)cost of doing business. While cyberspace encompasses practically any firm indeveloped economies and a large portion in developing ones, combatting such risks isdeemed a question of firm-specific responsibility: the situation resembles an ‘every manfor himself’ scenario. Consulting standard financial theory, rational utility-maximizinginvestors assume firm-specific (idiosyncratic) risk under expectations of additionalcompensation for shouldering such risk – they are economically incentivized. The omnipresence of cyberattacks challenges fundamental assumptions of the CapitalAsset Pricing Model, Optimal Portfolio Theory, and the concept of diversifiability. Thethesis problematizes underlying rationality notions by investigating the effect of acyberattack on stock volatility. Explicitly, the use of stock volatility as a proxy for riskallows for linking increased volatility to higher risk premiums and increased cost ofcapital. In essence, we investigate the following research question: What is the effect ofa disclosed cyberattack on stock volatility for firms listed in the USA?. Using event study methodology, we compile a cyberattack database for events between2010 and 2015 involving 115 firms listed on US stock exchanges. The specified timeperiod cover prevailing research gaps; due to literature paucity the focus on volatilityfits well. For a finalized sample of 189 events, stock return data is matched to S&P500index return data within a pre-event estimation window and a post-event window tocalculate abnormal returns using the market model. The outputs are used to estimateabnormal return volatility before and after each event; testing pre and post volatilityagainst each other in significance tests then approximates the event-induced volatility.Identical procedures are performed for all subsamples based on time horizon, industrybelonging, attack type, firm size, and perpetrator motivation. The principal hypothesis, that stock volatility is significantly higher after a cyberattack,is found to hold within both event windows. Evidence on firm-specific characteristics ismore inconclusive. In the long run, inaccessibility and attacks on smaller firms seem torender significantly larger increases in volatility compared to intrusion and attacks onlarger firms; supporting preexisting literature. Contrastingly, perpetrator motive appearsirrelevant. Generally, stocks are more volatile immediately after an attack, attributableto information asymmetry. For most subsamples volatility seem to diminish with time,following the Efficient Market Hypothesis. Summing up, disparate results raisequestions of the relative importance of contingency factors, and also about futuredevelopments within and outside academic research.

This thesis examines the impact of shocks in spot prices on long-term forward contracts in power markets. A unique comparison of efficiency of German and Hungarian power markets is provided. The risk premium on week-ahead forward contract is scrutinized by both data inspection and by unbiased forward rate hypothesis (UFRH) testing. Additionally, the ex-post market's prediction error for this product is explained by main drivers of spot electricity price, which are presented in section devoted to introduction to power markets. Expectedly, Hungarian forwards with longer time-to-delivery are found to react heavily on spot market shocks after controlling for changes in short-run marginal costs of conventional power plants. Such outcome applies both to intra-day and weekly time horizons. However, this evidence was not found for German market. These results point out to immaturity and the presence of inefficiencies in Hungarian power market. However, Hungarian risk premia on week-ahead and day-ahead forward products turn out to be considerably lower than for Germany. This was confirmed by UFRH tests on week-ahead forward contracts, where a significant risk premium was found in Germany as opposed to Hungarian risk premium. This finding is surprising since Hungarian spot prices are more prone to upward...

The thesis examines whether the role of credit rating prior to the announcement of credit rating change is the neglected factor explaining in large extent the paradox investigated in prior papers that downgrades influence the stock prices of company but upgrades not. It is motivated by the notion that credit rating changes from low credit rating classes influence the stock price of company more distinctively than changes from higher credit rating classes and there is proportionally more downgrades from low credit rating classes than upgrades. The large sample of credit rating changes including proportionally more upgrades from low credit rating classes than downgrades is collected and the results suggesting the influence of downgrades on stock prices of company and any influence of upgrades persist. Furthermore when controlled for credit rating prior to the announcement of credit rating change, magnitude of credit rating change, crossing the investment-speculative barrier, credit rating changes within and across credit rating categories, consecutive credit rating changes in the same direction and industry sector of issuer all the results are consistent with the original conclusions proposing significant stock price reaction to announcements of credit rating downgrades and no stock price response to...

The aim of this study is to gather insights into market efficiency and mechanisms that work in the financial markets. It provides a framework with an emphasis on liquidity and the failure of arbitrage that deepens our understanding of various financial crises. Described mechanisms are particularly relevant for the last financial crises - including 2007-2009, LTCM, and dot-com bubble. In the first chapter the concept of efficient markets is introduced. In the second chapter it is challenged from the point of view of noise trader theory and limits of arbitrage. The third chapter deals with market microstructure and liquidity. Last chapter shows importance and adverse effects of externalities, particularly of those causing liquidity spirals.