Ce travail propose une analyse de l’évaluation des capitaux propres de l’entreprise obtenue des modèles d’évaluation de la rente économique. La qualité des estimations dépend de la pertinence des hypothèses et du calibrage empirique de ces modèles. Dans un premier temps, les fondements théoriques des différentes hypothèses sur la croissance et/ou la persistance de la rente économique et de son influence sur l’évaluation des fonds propres sont analysés. S’appuyant sur le modèle des accroissements anormaux du résultat, nous montrons que la rente économique du nouvel investissement ou de l’accroissement anormal du résultat devrait converger vers zéro du fait des forces concurrentielles. Cette proposition, différente de ce qui est couramment admis suite au travail d’Ohlson et Juettner-Nauroth, apparaît influencer sensiblement l’estimation des fonds propres de l’entreprise. Une analyse asymptotique des multiples présentés dans le deuxième chapitre de cette thèse souligne ces aspects en dehors des biais et des difficultés que pourraient amener les mesures empiriques du phénomène. Le travail propose notamment une explication de la surévaluation systématique des fonds propres obtenue par le modèle des accroissements anormaux du résultat. Par la suite, une méthode d’estimation de la persistance de l’accroissement anormal du résultat par firme est proposé afin d’améliorer le calibrage de ce modèle. Dans le dernier chapitre, un modèle analytique synthétisant les deux grands types d’approche concernant la modélisation de la rente, le modèle des résultats résiduels et le modèle des accroissements anormaux du résultat, est proposé. Une équation de valorisation linéaire en est dérivée et est mobilisée afin de caractériser le contenu informationnel des prévisions de la variation du bénéfice à court terme avancées par les analystes financiers. / This research proposes an analysis of equity valuation of firm, obtained from the models valuing economic rents. The quality of the estimations depends on the pertinence of the hypothesis and the empirical calibration of these models. In the first place, the theoretical foundations of different hypotheses on the growth rate and/or the persistence level of economic rent and the influence of these hypotheses on equity valuation are analyzed. Through the abnormal earnings growth model, we show that the economic rent of the new investment or the abnormal earnings growth should converge towards zero due to the market competition. This proposition, different from Ohlson and Juettner-Nauroth’s assumption often adopted in prior studies, is found having sensitive influence on equity valuation. The asymptotic analysis of valuation ratios in the second chapter of this thesis underlines these aspects while being immune from the bias and the difficulties that the empirical studies on this issue could induce. This research notably proposes an explanation for the problem of systematic overvaluation of equity by the abnormal earnings growth model. In the second place, to improve the calibration of the abnormal earnings growth model, a method is proposed to estimate the firm-specific persistence level of the abnormal earnings growth. In the last chapter, an analytical model is proposed to synthesize the two main approaches concerning rent modeling: the residual income valuation model and the abnormal earnings growth model. A linear valuation equation is derived from the analytical model and mobilized to characterize the value relevance of the short-term earnings variation forecasted by financial analysts.

This essay considers the interplay between character narrators, the implied author, and the authorial audience in Octavia Butler’s Parable of the Talents. The aim of the study was to investigate how narrators, the implied author, and readers position themselves in relation to each other and in relation to the novel’s ethical dimensions. The theoretical framework is based on James Phelan’s theories on the rhetorical and ethical aspects of fiction. The essay argues that the implied author’s communication to the authorial audience is one of the reasons that the novel, like its prequel Parable of the Sower, often succeeds to function as warnings to the audience of dangers ahead. This is especially true regarding one of the implied author’s most consistent messages to the audience throughout the Parable novels: every choice has consequences, and those consequences need to be considered when we decide how to act and react in different circumstances, both as individuals and as a society.

I denna studie undersöks den känsla av författarnärvaro som präglar Asta Olivia Nordenhofs roman Penge på lommen. Genom att undersöka hur Nordenhofs ethos och persona förhåller sig till bokens berättartekniker, samt hur detta samverkar med berättarpåträngningar, är det möjligt att visa hur författaren, genom en paus i narrativet, förmedlar sin egen röst och sammansmälter sin litterära persona med sitt ethos. Detta resultat kontextualiseras genom att beskriva Nordenhofs litterära samtid i Danmark. Därigenom skapar uppsatsen förståelse för vilka etiska dimensioner som ryms i romanens berättartekniker, i synnerhet blickens ökande och minskande distans till romankaraktärerna. Avslutningsvis diskuteras författarnävaron utifrån blickens etiska aspekter.

Synthetic short positions constructed by equity options and stock loan short sells are linked by arbitrage. This thesis analyses the link by considering the implied volatility surface (IVS) at 80%, 100%, and 120% moneyness, and stock loan variables such as benchmark rate (rt), utilization, short interest, and transaction trends to inspect time-dependent structures between the two assets. By applying multiple multivariate time-series analyses in terms of vector autoregression (VAR) and the recurrent neural networks long short-term memory (LSTM) and gated recurrent units (GRU) with a sliding window methodology. This thesis discovers linear and complex relationships between the IVS and stock loan data. The three-day-ahead out-of-sample LSTM forecast of IV at 80% moneyness improved by including lagged values of rt and yielded 19.6% MAPE and forecasted correct direction 81.1% of samples. The corresponding 100% moneyness GRU forecast was also improved by including stock loan data, at 10.8% MAPE and correct directions for 60.0% of samples. The 120% moneyness VAR forecast did not improve with stock loan data at 26.5% MAPE and correct directions for 66.2% samples. The one-month-ahead rt VAR forecast improved by including a lagged IVS, at 25.5% MAPE and 63.6% correct directions. The presented data was optimal for each target variable, showing that the application of LSTM and GRU was justified. These results indicate that considering stock loan data when forecasting IVS for 80% and 100% moneyness is advised to gain exploitable insights for short-term positions. They are further validated since the different models yielded parallel inferences. Similar analysis with other equity is advised to gain insights into the relationship and improve such forecasts. / Syntetiska kortpositioner konstruerade av aktieoptioner och blankning med aktielån är kopplade med arbitrage. Denna tes analyserar kopplingen genom att överväga den implicerade volatilitetsytan vid 80%, 100% och 120% moneyness och aktielånvariabler såsom referensränta rt, låneutnyttjande, låneintresse, och transaktionstrender för att granska tidsberoende strukturer mellan de två tillgångarna. Genom att tillämpa multipel multidimensionell tidsserieanalys såsom vektorautoregression (VAR) och de rekursiva neurala nätverken long short-term memory (LSTM) och gated recurrent units (GRU). Tesen upptäcker linjära och komplexa samband mellan implicerade volatilitetsytor och aktielånedata. Tre dagars LSTM-prognos av implicerade volatiliteten vid 80% moneyness förbättrades genom att inkludera fördröjda värden av rt och gav 19,6% MAPE och prognostiserade korrekt riktning för 81,1% av prover. Motsvarande 100% moneyness GRU-prognos förbättrades också genom att inkludera aktielånedata, resulterande i 10,8% MAPE och korrekt riktning för 60,0% av prover. VAR-prognosen för 120% moneyness förbättrades inte med alternativa data på 26,5% MAPE och korrekt riktning för 66,2% av prover. En månads VAR-prognos för rt förbättrades genom att inkludera en fördröjd implicerad volatilitetsyta, resulterande i 25,5% MAPE och 63,6% korrekta riktningar. Presenterad statistik var optimala för dessa variabler, vilket visar att tillämpningen av LSTM och GRU var motiverad. Därav rekommenderas det att inkludera aktielånedata för prognostisering av implicerade volatilitetsytor för 80% och 100% moneyness, speciellt för kortsiktiga positioner. Resultaten valideras ytterligare eftersom de olika modellerna gav dylika slutsatser. Liknande analys med andra aktier är rekommenderat för att få insikter i förhållandet och förbättra sådana prognoser.

According to Skolverket, the Swedish school has two missions: conveying knowledge and teaching values. These values are taught through the common principles (värdegrund) and instruct students about democratic values and human rights. However, Skolverket also reports that students lack such knowledge. Therefore, this essay aims to create a module with the main purpose of formulating and teaching the common principles, by using Phaswane Mpe's Welcome to Our Hillbrow, a text with the ability of presenting ethical issues whilst also making the reader respond to them. To achieve this, the values of the common principles will be extracted with the help of virtue ethics, which creates a conjunction with the book, where three topics are selected: sexism, gender identity and societal transformation. Virtue ethics, representing the common principles, together with Adichie’s definition of African feminism inform the analysis of sexism and gender inequality in the book and show how they are prevalent and extensive. Societal transformation is conceptualised and investigated through the use of narratology. Sexism and gender inequality are located in the horizontal plane of an arena, where the vertical expansion of narrative levels creates the urge for societal transformation. Such an expansion is made possible by an implied author, which provides the effect needed for reader inclusion. As such, Welcome to Our Hillbrow is described to entail an ethical challenge, that forces a responsible reader to emerge. Issues of sexism and gender inequality are then used together with the arena of societal transformation to construct a module in English 7, where students may themselves become reasonable readers through a process of critical self-reflection, a vital part of virtue ethics. This is done by employing Socratic and deliberative dialogue and an affective-humanistic approach, which together promote democratic values and human rights.

In this thesis will the question of how to construct implied volatility surfaces in a robust and arbitrage free way be investigated. To be able to know if the solutions are arbitrage free was an initial investigation about arbitrage in volatility surfaces made. From this investigation where two comprehensive theorems found. These theorems came from Roper in \cite{Roper2010}. Based on these where then two applicable arbitrage tests created. These tests came to be very important tools in the remaining thesis.The most reasonable classes of models for modeling the implied volatility surface where then investigated. It was concluded that the classes that seemed to have the best potential where the stochastic volatility models and the parametric representation models. The choice between these two classes where concluded to be based on a trade-off between simplicity and quality of the result. If it where possible to make the parametric representation models improve its result the best applicable choice would be that class. For the remaining thesis was it therefore decided to investigate this class. The parametric representation model that was chosen to be investigated where the SVI parametrization family since it seemed to have the most potential outside of its already strong foundation.The SVI parametrization family is diveded into 3 parametrizations, the raw SVI parametrization, the SSVI parametrization and the eSSVI parametrization. It was concluded that the raw SVI parametrization even though it gives very good market fits, was not robust enough to be chosen. This ment that the raw SVI parametrization would in most cases generate arbitrage in its surfaces. The SSVI model was concluded to be a very strong model compared to the raw SVI, since it was able to generate completely arbitrage free solutions with good enough results. The eSSVI is an extended parametrization of the SSVI with purpose to improve its short maturity results. It was concluded to give small improvements but with the trade of making the optimization procedure harder. It was therefore concluded that the SSVI parametrization might be the better application.To try to improve the results of the SSVI parametrization was a complementary procedure developed which got named the calibrated SSVI method. This method compared to the eSSVI parametrization would not change the parametrization but instead focusing on calibrating the initial fit that the SSVI generated. This method would heavily improve the initial fit of the SSVI surface but was less robust since it generated harder cases for the interpolation and extrapolation. / I det här examensarbetet undersöks frågan om hur man bör modellera implied volatilitetsytor på ett robust och arbitragefritt sätt. För att kunna veta om lösningarna är arbigtragefria börjades arbetet med en undersökning inom arbitrageområdet. De mest heltäckande resultatet som hittades var två theorem av Roper i \cite{Roper2010}. Baserat på dessa theorem kunde två applicerbara arbitragetester skapas som sedan kom att bli en av hörnstenarna i detta arbete. Genom att undersöka de modellklasser som verkade vara de bästa inom området valdes den parametriseringsbeskrivande modellklassen.  I denna klass valdes sedan SVI parametriseringsfamiljen för vidare undersökning eftersom det verkade vara den familj av modeller som hade störst potential att uppnå jämnvikt mellan enkel applikation samt bra resultat.  För den klassiska SVI modellen i SVI familjen drogs slutsatsen att modellen inte var tillräcklig för att kunna rekommenderas. Detta berodde på att SVI modellen i princip alltid genererade lösningar med arbitrage i. SVI modellen genererar dock väldigt bra lösningar mot marknadsdatan enskilt och kan därför vara ett bra alternativ om man bara ska modellera ett implied volatilitetssmil. SSVI modellen ansågs däremot vara ett väldigt bra alternativ. SSVI modellen genererar komplett aribragefria lösningar men har samtidigt rimligt bra marknadspassning.  För att försöka förbättra resultaten från SSVI modellen, var en kompleterande metod kallad den kalibrerade SSVI metoden skapad. Denna metod kom att förbättra marknadspassningen som SSVI modellen genererade men som resultat kom robustheten att sjunka, då interpoleringen och extrapoleringen blev svårare att genomföra arbitragefritt.

The implied volatility surface plays an important role for Front office and Risk Management functions at Nasdaq and other financial institutions which require mark-to-market of derivative books intraday in order to properly value their instruments and measure risk in trading activities. Based on the aforementioned business needs, being able to calibrate an end of day implied volatility surface based on new market information is a sought after trait. In this thesis a statistical learning approach is used to calibrate the implied volatility surface intraday. This is done by using OMXS30-2019 implied volatility surface data in combination with market information from close to at the money options and feeding it into 3 Machine Learning models. The models, including Feed Forward Neural Network, Recurrent Neural Network and Gaussian Process, were compared based on optimal input and data preprocessing steps. When comparing the best Machine Learning model to the benchmark the performance was similar, indicating that the calibration approach did not offer much improvement. However the calibrated models had a slightly lower spread and average error compared to the benchmark indicating that there is potential of using Machine Learning to calibrate the implied volatility surface. / Implicita volatilitetsytor är ett viktigt vektyg för front office- och riskhanteringsfunktioner hos Nasdaq och andra finansiella institut som behöver omvärdera deras portföljer bestående av derivat under dagen men också för att mäta risk i handeln. Baserat på ovannämnda affärsbehov är det eftertraktat att kunna kalibrera de implicita volatilitets ytorna som skapas i slutet av dagen nästkommande dag baserat på ny marknadsinformation. I denna uppsats används statistisk inlärning för att kalibrera dessa ytor. Detta görs genom att uttnytja historiska ytor från optioner i OMXS30 under 2019 i kombination med optioner nära at the money för att träna 3 Maskininlärnings modeller. Modellerna inkluderar Feed Forward Neural Network, Recurrent Neural Network och Gaussian Process som vidare jämfördes baserat på data som var bearbetat på olika sätt. Den bästa Maskinlärnings modellen jämfördes med ett basvärde som bestod av att använda föregående dags yta där resultatet inte innebar någon större förbättring. Samtidigt hade modellen en lägre spridning samt genomsnittligt fel i jämförelse med basvärdet som indikerar att det finns potential att använda Maskininlärning för att kalibrera dessa ytor.

Options are an important part in today's financial market. It's therefore of high importance to be able to understand when options are overvalued and undervalued to get a lead on the market. To determine this, the relation between the volatility of the underlying asset, called realized volatility, and the market's expected volatility, called implied volatility, can be analyzed. In this thesis five models were investigated for modeling the relation between implied and realized volatility. The five models consisted of one Ornstein–Uhlenbeck model, two autoregressive models and two artificial neural networks. To analyze the performance of the models, different accuracy measures were calculated for out-of-sample forecasts. Signals from the models were also calculated and used in a simulated options trading environment to get a better understanding of how well they perform in trading applications. The results suggest that artificial neural networks are able to model the relation more accurately compared to more traditional time series models. It was also shown that a trading strategy based on forecasting the relation was able to generate significant profits. Furthermore, it was shown that profits could be increased by combining a forecasting model with a signal classification model. / Optioner är en viktig del i dagens finansiella marknad. Det är därför viktigt att kunna förstå när optioner är över- och undervärderade för att vara i framkant av marknaden. För att bestämma detta kan relationen mellan den underliggande tillgångens volatilitet, kallad realiserad volatilitet, och marknadens förväntade volatilitet, kallad implicit volatilitet, analyseras. I den här avhandlingen undersöktes fem modeller för att modellera relationen mellan implicit och realiserad volatilitet. De fem modellerna var en Ornstein–Uhlenbeck modell, två autoregressiva modeller samt två artificiella neurala nätverk. För att analysera modellernas prestanda undersöktes olika nogrannhetsmått för prognoser från modellerna. Signaler från modellerna beräknades även och användes i en simulerad optionshandelsmiljö för att få en bättre förståelse för hur väl de presterar i en handelstillämpning. Resultaten tyder på att artificiella neurala nätverk kan modellera relationen bättre än mer traditionella tidsseriemodellerna. Det visades även att en handelsstrategi baserad på prognoser av relationen kunde generera en signifikant vinst. Det visades dessutom att vinster kunde ökas genom att kombinera en prognosmodell med en modell som klassificerar signaler.

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[pt] Esta pesquisa investiga primeiramente, por meio de regressões, a relação entre as volatilidades implícitas das opções e os retornos futuros de 20, 40 e 60 dias das ações subjacentes no mercado acionário brasileiro. Essas regressões são então submetidas a testes de heterocedasticidade para garantir que não são regressões espúrias. Por fim, submetemos os resultados a um teste de robustez que confirma as regressões válidas e verifica a presença de autocorrelação nas séries de retornos futuros. O período analisado é de janeiro de 2011 a dezembro de 2021 em um total de onze anos completos. Apesar de apresentarem coeficientes de regressão significativos, nem todas essas regressões passam pelos testes, e sempre deve-se ter cautela ao usar uma volatilidade implícita de opção como sendo capaz de prever retornos das ações subjacentes no mercado brasileiro. / [en] This research first investigates, through regressions, the relationship between the implied volatilities of options and the future returns of 20, 40 and 60 days of the underlying stocks within the Brazilian stock market. These regressions are then subjected to heteroscedasticity tests to ensure that they are not spurious regressions. Finally, we submit the results to robustness tests to confirm the valid regressions and verify the presence of autocorrelation in the series of future returns. The period under analysis is from January 2011 to December 2021, totalling 11 years. Despite having significant regression coefficients, not all of these regressions pass the tests, and one should always exercise caution when using an option implied volatility as a predictor of underlying equity returns in the Brazilian market.