Bakgrund: 4 av 5 svenskar äger aktier i någon form och det är många som är intresserade av att maximera sin avkastning. Det har lett till att det skrivs mycket i media om olika sätt att få avkastning högre än marknaden. Om det skulle vara möjligt att nå överavkastning är det en indikation på att marknaden inte är effektiv. Syfte: Syftet med studien är att undersöka om det historiskt har gått att nå en överavkastning genom tillämpa momentum- eller motsatstrategin på den svenska aktiemarknaden. Syftet är även att testa om den svenska aktiemarknaden har varit effektiv i svag form. Genomförande: Momentumstrategin testades genom att portföljer formades med de tio aktier som har haft högst relativ prisstyrka de senaste sex månaderna. Portföljernas marknadsjusterade avkastning har sedan följts i sex månader. Motsatsstrategin testades genom att vinnarportföljer formades med de tio aktier som har haft högst avkastning de senaste tre åren och förlorarportföljer formades för de med lägst avkastning. Portföljernas marknadsjusterade avkastningar under de kommande tre åren jämfördes sedan med varandra. Slutsats: Vi har kommit fram till att det har gått att nå en överavkastning med hjälp av momentumstrategin och att den har fungerat bäst i perioder av stabila uppgångar. Det har däremot inte gått att få överavkastning med hjälp av motsatsstrategin. Vi menar att resultatet beror på att marknaden underreagerar. Därmed kan vi säga att den svenska aktiemarknaden under den undersöka tidsperioden inte har varit effektiv i svag form. / Background: 4 out of 5 Swedes own stocks in some form and many people are interested in maximising their profits. This has led to a lot of publicity in ways to get profits higher than the market. The eventual possibility to receive abnormal returns indicates that the market is inefficient. Purpose: The purpose of the study is to investigate if it historically has been possible to receive abnormal returns by implementing momentum- and contrarian strategies on the Swedish stock market. The purpose is also to test if the Swedish stock market has been efficient in weak form. Implementation: The momentum strategy was tested by forming portfolios consisting of the ten stocks with the highest relative price strength over the last six months. The portfolio abnormal returns were then followed for the following six months. The contrarian strategy was tested by forming winner portfolios consisting of the ten stocks with the highest abnormal returns over the last three years. Loser portfolios were formed of the ten stocks with the lowest abnormal returns over the last three years. The portfolios abnormal returns were then compared to each other for the following three years. Conclusion: We have reached the conclusion that it has been possible to receive abnormal returns by using the momentum strategy. It has been the most successful in periods of steady raises. The contrarian strategy has not generated any excess returns. We believe that reason for the results is that the market under reacts. Therefore we can state that the Swedish stock market not has been efficient in weak form during the examined period.

In this thesis a kinetic theory for spin-1/2 particles is given a brief overview, focusing on the derivation of an evolution equation for the quasiprobability distribution function used in the theory to describe certain types of quantum plasma. The current theory is expanded upon by exploring conservation laws. A local conservation law for momentum is derived using two different expressions for electromagnetic momentum, given by Abraham and Minkowski respectively. There has been some controversy over which of these expressions should be used; in the case considered here the expression given by Minkowski seems to be more suitable. Based on the conservation law for momentum, a conservation law for angular momentum is also derived.

The study is based on the study of Jegadeesh and Titman (1993, 2001) which found evidence of succesfull trading strategies which yielded significant positive abnormal returns by exploiting a momentum pattern in stock prices. The purpose of this study is to contribute with empirical results to the discussions of efficient markets, momentum effects and behavioral finance by providing evidence from the Swedish stock market between the years 1998 and 2013. The conclusion is that there exists a Momentum Effect on the Swedish stock market. The utilization of momentum strategies yields significant positive abnormal returns. The Efficient Market Hypothesis is a model which might hold in the long-term, but shows limitations in the short-term. The implications of the results of this study are that short-term investor behavior and momentum profits might be partially explained by behavioral finance models but the origin of the momentum profits need to be further evaluated.

Beams of light can carry spin and orbital angular momentum. Spin angular momentum describes how the direction of the electric field rotates about the propagation axis, while orbital angular momentum describes the rotation of the field amplitude pattern. These concepts are well understood for monochromatic beams, but previous theoretical studies have constructed polychromatic superpositions where the connection between angular momentum and rotation of the electric field becomes much less clear. These states are superpositions of two states of light carrying opposite signs of angular momentum and slightly detuned frequencies. They rotate at the typically small detuning frequency and thus we call them slowly rotating modes of light. Strangely, some of these modes appear to rotate in the direction opposing the sign of their angular momentum, while others exhibit overall rotation with no angular momentum at all! These findings have been the subject of some controversy, and in 2012, Susanna Todaro (HMC ’12) and I began work on trying to shed light on this “angular momentum paradox." In this thesis, I extend previous work in theory, simulation, and experiment. Via theory and modeling in Mathematica, I present a possible intuitive explanation for the angular momentum paradox. I also present experimental realization of slowly rotating spin superpositions, and outline the steps necessary to generate slowly rotating orbital angular momentum superpositions.

No description available.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-04-24T13:48:24Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese - Valéria Saturnino - Versão Final.pdf: 2311610 bytes, checksum: 50e78bde81f7f2bbf611974dc45a5847 (MD5) / Made available in DSpace on 2017-04-24T13:48:24Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese - Valéria Saturnino - Versão Final.pdf: 2311610 bytes, checksum: 50e78bde81f7f2bbf611974dc45a5847 (MD5) Previous issue date: 2016-12-09 / Esta tese teve por objetivo desenvolver uma nova sistemática de otimização de portfólios a partir da premissa da existência de desvios comportamentais dos investidores no mercado brasileiro. Para tanto, realizou-se uma ampla pesquisa bibliográfica buscando verificar a ocorrência destes desvios no Brasil e no mundo. Em seguida, foi desenvolvida a metodologia de pesquisa, a qual está dividida na execução de testes para avaliar as três hipóteses previstas, quais sejam: (1) de que ocorre o Overreaction no mercado de capitais brasileiro; (2) de que retornos anormais podem ser explicados tanto por variáveis fundamentalistas como comportamentais; e (3) de que é possível criar uma sistemática de otimização de carteiras que considere tanto os aspectos fundamentalistas como os comportamentais na decisão acerca do rebalanceamento dos pesos. O primeiro resultado obtido foi que não se pode rejeitar a ocorrência do Overreaction no Brasil no longo prazo. Além disso, os retornos das carteiras foram por um lado adequadamente explicados pelas variáveis do modelo de cinco fatores de Fama e French (2015), e por outro pela regressão do CSAD, a qual caracteriza os desvios de comportamento dos investidores. Sendo assim, foi criada a carteira recomendada e, juntamente com as carteiras perdedoras e vencedoras, foram analisados os retornos nos 20 trimestres seguintes, utilizando cinco métodos de otimização diferentes. Os resultados obtidos permitiram concluir que a sistemática proposta de monitoramento funciona melhor nas carteiras vencedoras, mas as carteiras de melhor desempenho no Brasil são aquelas baseadas em análises fundamentalistas, corroborando com a previsão de eficiência do mercado de capitais brasileiro. / This thesis aimed to develop a new systematic optimization of portfolios based on the premise of the existence of behavioral deviations of investors in the Brazilian market. For that, an extensive bibliographical research was carried out to verify the occurrence of these deviations in Brazil and in the world. Next, the research methodology was developed, which is divided into the execution of tests to evaluate the three predicted hypotheses, namely: (1) that Overreaction occurs in the Brazilian capital market; (2) that abnormal returns can be explained by both fundamentalist and behavioral variables; And (3) that it is possible to create a portfolio optimization system that considers both fundamentalist and behavioral aspects in the decision on rebalancing weights. The first result was that the overreaction in Brazil can not be rejected in the long run. Moreover, portfolio returns were on the one hand adequately explained by the variables of the five-factor model of Fama and French (2015), and on the other, by the regression of the CSAD, which characterizes the behavioral deviations of the investors. Thus, the recommended portfolio was created and, together with the losing and winning portfolios, the returns for the next 20 quarters were analyzed using five different optimization methods. The results obtained allowed us to conclude that the systematic monitoring proposal works best in the winning portfolios, but the best performance portfolios in Brazil are those based on fundamentalist analyzes, corroborating with the prediction of efficiency of Brazilian capital market.

Bakgrund: Omfattande forskning har visat på att investeringsstrategier kan användas för att kontinuerligt uppnå överavkastning gentemot index. Multiplarna EV/EBIT och EV/EBITDA är vanliga inslag i investeringsstrategier eftersom de båda ses som en nära approximation av ett företags operativa kassaflöde, samtidigt som de tar hänsyn till företagets kapitalstruktur. Även om det bara är avskrivningarna som skiljer multiplarna åt anse r vi att andelen investeringar i ett företag utgör en fundamental grund för dess långsiktiga värdeskapande. Av denna anledning finns det ett intresse i att undersöka hur kapitalintensiteten påverkar en investeringsstrategis förmåga att generera överavkastning som grundar sig på multiplarna EV/EBIT och EV/EBITDA. Syfte: Syftet med denna studie är att jämföra multiplarna EV/EBIT och EV/EBITDAs förmåga att generera överavkastning på Stockholmsbörsen. Metod: För studien har en kvantitativ metod använts med en deduktiv ansats för att samla in och bearbeta data om bolag listade på Stockholmsbörsen under perioden 2005 - 2016. Dessa bolag har utgjort grunden för tolv olika portföljer som skilt sig åt med avseende på multipel och innehavsperiod. För att statistiskt säkerställa studiens resultat har parvisa t-tester använts. Resultat: Av tolv portföljer har nio uppnått riskjusterad överavkastning gentemot jämförelseindex OMXSPI. Resultatet har kunnat säkerställas statistiskt för sju portföljer inom dubbelsidiga konfidensintervall på mellan 90 - 99 procent. En investering i låga multipelvärden för EV/EBIT tillsammans med en innehavsperiod på sex månader genererar den högsta ackumulerade avkastningen, både innan och efter justering för risk. I kontrast genererar en investering i höga multipelvärden för EV/EBIT den lägsta ackumulerade avkastningen under den studerade tidsperioden. / Background: Extensive research has shown that investment strategies can be used to achieve continuous abnormal returns in comparison to an index. Many investment strategies are based on the multiples EV/EBIT and EV/EBITDA. These multiples suffice as an approximation of the company’s operational cash flow while taking into account the capital structure. Even though it is only the depreciation and amortization that sets the two multiples apart, we argue that the need for investments constitute a fundamental part of creating long term stakeholder value. For this reason we find it interesting to study how the capital intensity affects an investment strategy’s ability to generate returns based on the multiples EV/EBIT and EV/EBITDA. Aim: The aim with this study is to compare the multiples EV/EBIT and EV/EBITDA’s ability to generate returns on the Stockholm Stock Exchange. Methodology: The study has used a quantitative method with a deductive approach in order to collect and process data for companies listed on the Stockholm Stock Exchange during the time period 2005 – 2016. These companies have constituted the base for a ranking process, ultimately leading to the creation of twelve portfolios that differ with regard to the type of multiple and holding period. In order to statistically verify the results of the study we have used pairwise t-tests. Results: Out of twelve portfolios nine have achieved risk adjusted abnormal returns in comparison with the index OMXSPI. The results could be verified statistically for seven portfolios within a double-sided confidence interval of between 90-99 percent. An investment in low multiple values for EV/EBIT with a holding period of six months generates the highest accumulated return, both before and after adjustment for risk. In contrast, an investment in high multiple values for EV/EBIT generates the lowest accumulated return during the studied time period.

La performance sportive est influencée par de nombreux facteurs, lesquels s’influencent eux-mêmes réciproquement. La complexité de ces facteurs et de leurs relations ayant été négligée par les chercheurs, l’objet de la présente thèse était de rendre compte de cette complexité, à l’aide de méthodes empruntées à l’approche dynamique. Nous avons pu montrer que (a) les joueurs de football les plus experts construisent leur représentations du jeu en cours (les liens entre actions réalisées sur le terrain) avec des niveaux de complexité les plus élevés; (b) en aviron, une organisation motrice complexe, impliquant des interactions entre de nombreuses composantes, sous-tend la génération des mouvements de rame en cours; (c) le momentum psychologique en aviron se caractérise par des changements psychologiques et de performance qui s’inscrivent dans l’histoire de la performance; et (d) la performance excellente se développe à partir des interactions en cours entre les facteurs personnels et environnementaux couplés. Ces différents éclairages montrent l’intérêt d’une approche de la complexité pour comprendre les processus de performance. / The processes involved in human performance seem inherently complex and dynamic. For example, in order to “read the game”, a soccer player must integrate all the information from the ongoing movements and positions of team members, the opponents, the relative positions between them, where the ball is located, etc. Furthermore, an individual’s motor performance, which is particularly crucial in sports, depends on various simultaneous processes at different levels of the motor system: Cells, muscles, limbs, the brain, etc. In addition, individuals and teams do not perform in a void, but in achievement contexts, in which they strive for their goals, and their psychological states and performance may fluctuate as a function of many personal and environmental factors. For example, an athlete may enter a positive or negative spiral when perceiving that he or she is progressing or regressing in relation to the preferred goal or outcome (e.g., the victory). This perception of progress and regress, and the positive and negative psychological and behavioral (performance) changes accompanying this perception, are called positive and negative psychological momentum (PM; e.g., Gernigon, Briki, & Eykens, 2010). Positive and negative PM can emerge from one’s (or the opponent’s) mistakes, referee decisions, crowd behaviors, one’s psychological and physical state at a certain moment, and the interactions between these factors (Taylor & Demick, 1994). In addition, switching from performance on a relatively short time frame to a long-term process, individuals develop their abilities over multiple years, and hence over many practice or competition occasions. Ultimately, very few individuals develop world-class performance (e.g., winning Olympic medals), and their excellent abilities develop out of a combination of a variety of personal and environmental factors in interaction (e.g., motivation, coaching, family support, practice; Simonton, 1999). The current dissertation aims to capture complex dynamic performance-related processes, including the topics illustrated above. This means that we examine complexity at different levels (psychological, behavioral), time scales (from one training or competition session up to a career), as well as the interrelation between the processes across different levels and time scales.

The study examined the momentum in the fundamentals of companies over time, and whether the information content in the momentum of the fundamentals improved the understanding of the long-standing price momentum and earnings momentum anomalies on the Johannesburg Stock Exchange (JSE). Fundamental momentum is defined as the difference between the change of a fundamental variable over consecutive time periods. The study included all industrial companies that were listed on the JSE between the period January 1990 and December 2013. The purpose of the study was to investigate whether price momentum or earnings momentum was subsumed by fundamental momentum. Price momentum and earnings momentum are long-standing anomalies that have been widely researched, yet no definitive explanation has been provided in the literature. The objective of the study was to improve the understanding of price momentum and earnings momentum through the analysis of fundamental momentum. The study also provided insight into the persistence of fundamental momentum of earnings. The study tested the profitability of the price momentum, earnings momentum and the fundamental momentum of earnings trading strategies. The research hypotheses were formulated and tested using equal-weighted sort analysis. The sustainability of fundamental momentum of earnings was also analysed. The size and value risk factors were taken into account to ensure that the results were not influenced by such risk factors. The Fama and French three-factor model was employed to test whether the results captured one of these risk effects. The fourth research question investigated whether the fundamental momentum of an underlying component of earnings increased the persistence of the fundamental momentum of future earnings. Earnings were shown to be mean reverting over time, and therefore, the expectation was that positive or negative fundamental momentum of earnings was not sustainable over a prolonged period of time. However, by decomposing earnings into the accrual and cash flow components, and their respective sub-components, the study undertook regression analysis to see whether a specific component of earnings could improve the sustainability of fundamental momentum. The final research question tested whether price momentum and/or earnings momentum was subsumed by fundamental momentum. Two-way analysis was conducted to test whether the strategies captured similar effects. Sort analysis was used by first constructing equal-weighted portfolios based on either price momentum or earnings momentum. Each portfolio was then further subdivided based on the fundamental momentum of earnings. The profitability of the resultant portfolios was then compared with the initial portfolio. The results confirmed that the price momentum and earnings momentum anomalies were present on the JSE for the sample selected for the study. The fundamental momentum of earnings trading strategy was also shown to be a profitable trading strategy for the extreme quintile portfolios. Using the Fama-MacBeth regression methodology, size and value effects were not found to impact the results across all three momentum strategies. A behavioural overreaction or underreaction hypothesis was argued to explain the profitability of the fundamental momentum of earnings strategy. The market was shown to anticipate the earnings surprise that resulted in earnings momentum up to 12 months prior to portfolio formation. Similarly, the market anticipated fundamental momentum of earnings 12 months prior to the earnings announcement. The fundamental momentum of future earnings was shown to be more sustainable when the fundamental momentum of the cash flow component of prior earnings was higher than the fundamental momentum of the accrual component of prior earnings. This result did not give insight into the nominal size effect of the underlying earnings components, rather, it only gave insight into the rates of change of the earnings components. The final result of the study showed that price momentum and fundamental momentum captured different effects. However, the earnings momentum and fundamental momentum results were not as clear cut. Both strategies used a variant of earnings to construct the quintile portfolios and thus it was very plausible that they captured a similar effect. The study contributed to the current literature in a number of ways. A new trading strategy based on the fundamental momentum of earnings was tested. Fundamental momentum of earnings as a trading strategy has yet to be defined; as a result, it has not been researched prior to this study. Given the results, it may be seen as a derivative of earnings momentum. Understanding the sustainability of fundamental momentum of future earnings was also researched. The final contribution of the study was the two-way analysis of price momentum and fundamental momentum, and earnings momentum and fundamental momentum. / Thesis (PhD)--University of Pretoria, 2016. / tm2016 / Financial Management / PhD / Unrestricted

Momentum has been a persistent and robust factor in explaining excess future returns, generating great interest from investors and financial analysts. Following the financial crisis of 2008 and the Covid-19 pandemic, there have been instances of significant momentum crashes. US Equity funds are used to gain insights about the properties of momentum and its predictive ability. Momentum performance is evaluated over the period 2000 to 2023. A multifactor model is developed, using factor attribution to explain the impact on fund performance over time by factors such as risk, size, value-growth orientation and momentum. Conclusions can be made that while momentum have previously been successful in predicting future returns, particularly for growth-oriented funds, recent market situations have lead to underperformance. The multifactor model, incorporating size and value-growth orientation, suggests that momentum is not entirely responsible for the poor performance following the Covid-19 crisis. / Momentum har historiskt sett varit en framgångsrik faktor för att predicera framtida avkastning, vilket har skapat stort intresse från investerare och finansiella analytiker. Efter finanskrisen 2008 och Covid-19 pandemin har det skett signifikanta momentumkrascher. Amerikanska aktiefonder används för att undersöka egenskaperna hos momentum och dess prediktiva förmåga. Prestationen av momentum utvärderas under tidsperioden 2000 till 2023. En multifaktormodell utvecklas, som använder faktor-attribution för att förklara hur fonders avkastning påverkas över tid av faktorer såsom risk, marknadsvärde, värde/tillväxt-orientering och momentum. En slutsats dras att även fast momentum har presterat väl historiskt för att predicera framtida avkastning, särskilt för tillväxt-orienterade aktiefonder, så har den senaste tidens marknadsrörelser lett till underprestation. Multifaktormodellen, som innehåller marknadsvärde och värde/tillväxt-orientering, indikerar att momentum inte är en lika stor anledning till underavkastningen efter Covid-19 krisen.