Denna uppsats undersöker om två olika momentumstrategier applicerat på mindre bolag i Sverige kan generera överavkastning. Momentumstrategier är investeringsstrategier som bygger på historisk prisdata och enligt den effektiva marknadshypotesen ska dessa inte kunna ge en överavkastning på en svagt effektiv marknad. Flertalet studier har dock hittat bevis för att dessa fungerar, och även att momentumavkastningen ofta är större för mindre bolag än stora bolag. Studiens urval är samtliga bolag som är noterade på NASDAQ Stockholm under tidsperioden 2007-2016. Vi följer Fama och Frenchs (2008) storleksdefinitioner och sorterar in bolagen i tre kategorier efter deras börsvärde (stora, små och mikrobolag) och vi bygger sedan portföljer med bolagen som kategoriseras som små. Portföljernas avkastning riskjusteras med Fama och Frenchs (1993) trefaktormodell. Studien finner att ingen av momentumstrategierna genererar en statistiskt signifikant överavkastning på den svenska marknaden under perioden.

This paper examines the efficiency of the Swedish stock market, specifically the Large cap list of the Stockholm stock exchange. This is achieved by implementing the relative strength method of investing during the decade of 2010-2020 and evaluate the results in contrast to the Efficient Market Hypothesis. The relative strength method applied in this paper is the similar strategy that Jagadeesh & Titman (1993) utilized. In short, the strategy is based on buying the historically best performing stocks whilst selling short the previous worst performers. Additionally, the risks associated with the method were examined with the risk measurements of the Jensen Alpha and the Modigliani risk-adjusted performance. The results indicate that the relative strength method is unable to consistently generate above-market returns, so that the study is unable to reject the Efficient Market Hypothesis. In addition, the relative strength method is unable to justify the risks associated.

The objective of this work is to develop a near-infrared laser device capable of emitting orbital angular momentum (OAM) light. The prototyped device must be suitable for compact, energy-saving optical communication applications. Integrated OAM lasers will revolutionize high-capacity data transmission over any telecommuni- cation network environment, as OAM light can be guided and transmitted through kilometers of optical fibers and propagated in free space and underwater. Several methods for generating OAM light employing various complex monolithic and hybrid integration methods have been demonstrated. In this work, microscale integrated spiral phase plates (SPPs) are chosen to convert the laser beam output into an OAM mode. The concept and design fundamentals of SPPs are discussed, followed by the SPP fabrication process and their implementation in a high-speed communication setup and then integration with a semiconductor laser. SPPs are fabricated by a novel direct laser writing that provides the possibility to rapidly prototype 3D photonic structures via a two-photon polymerization pro- cess. After fabrication, SPPs are used in a fine-tuned free-space optical experimental setup that requires high-precision intercomponent alignment to test the high-speed OAM communication system and analyze the quality of OAM modes, resulting in high-purity OAM signals at data rates up to 1.8 Gbit/s – limited by the avalanche photodetector (APD) frequency response. The fabricated 20-μm-diameter SPPs were the smallest reported in the literature to date for optical characterization. A proof-of-concept monolithic light-emitting array, as a highly integrated OAM laser source, is further proposed for telecommunications and other applications. SPP-integrated 940-nm vertical-cavity surface-emitting laser (VCSEL) array chips that are relatively low-cost, have a small footprint, and are manufacturable in high volumes are developed. SPPs with topological charge modulus values from 1 to 3 are fabricated on the VCSEL arrays, demonstrating OAM modal purities up to ∼65%. The experimentally evaluated data rates in the OAM setup showed consistently sta- ble links up to 2.0 Gbit/s with a bit error ratio of ∼ 1.6 × 10−8 (APD-limited). The challenges of SPP-laser integration are summarized, with the conclusion that the widespread adoption of OAM is limited by the availability of practical integrated solutions for OAM generation and detection.

What do investors' searches for public information reveal about their subsequent trading strategies? Does their search for information support the hypothesis of market efficiency or does it lend support to the idea that investors have behavioral biases. Using Google Trends, we find that the volume of Google searches about feeder cattle is associated with re-enforcement of momentum trading in a manner consistent with a positive feedback mechanism. Further, we find evidence that search volume for "cattle" is associated with higher volatility and thus amplifies the positive feedback trading mechanism, while the search volume for "corn", a major input to cattle production, is associated with a reduction in volatility.

What do investors' searches for public information reveal about their subsequent trading strategies? Does their search for information support the hypothesis of market efficiency or does it lend support to the idea that investors have behavioral biases. Using Google Trends, we find that the volume of Google searches about feeder cattle is associated with re-enforcement of momentum trading in a manner consistent with a positive feedback mechanism. Further, we find evidence that search volume for "cattle" is associated with higher volatility and thus amplifies the positive feedback trading mechanism, while the search volume for "corn", a major input to cattle production, is associated with a reduction in volatility.

Attentional biases occur with various psychological disorders, including drugaddiction and anxiety. Conditioned reinforcement likely plays a role in maintainingattentional biases to stimuli associated with reinforcement for unwanted behavior. Theobserving-response procedure is considered a model of attending as reflected byresponding maintained by conditioned reinforcement. Effects of primary reinforcement on the persistence of observing have been studied in the framework of behavioral momentum theory. Studies have shown observing-responses to be more resistant tochange in contexts arranging relatively higher rates of primary reinforcement. Recently, behavioral momentum theory has been extended to describe the effects of primary reinforcement context in relapse phenomena. The present thesis aimed to extend research on the resistance to change of observing to animal models of relapse. Pigeons responded on a two-component multiple schedule of observing-response procedures. In a rich component, observing responses produced stimuli correlated with a high rate of variableinterval (VI) food reinforcement (Rich S+). In a lean component, observing responses produced stimuli correlated with a low rate of VI food reinforcement (Lean S+). Following stable performance, responding was extinguished by removing food and S+ presentations. After extinction, relapse was assessed by reinstatement tests consisting of response-independent presentations of food or S+. Replicating earlier results, observingand food-key responding was more resistant to extinction in the Rich component. Food reinstatement had no systematic effect on extinguished food- and observing-key responding. However, S+ reinstatement resulted in relapse of extinguished observingand food-key responding. Relapse during S+ reinstatement was greater in the Rich component than the Lean component. Reinstatement of responding by S+ presentations resulted in a greater overall increase in responding on the food-key relative to the observing-key. This result suggests that an important functional relationship between the presence of S+ stimuli and increased rates of primary reinforcement for food key responding remained intact during extinction. The results show that observing is susceptible to relapse, and the magnitude of relapse depends on baseline primary reinforcement rate in a context.

Behavioral momentum theory proposes that the persistence of behavior when exposed to disruptors provides an appropriate measure of the strength of behavior. Basic research has consistently demonstrated that behaviors that occurred in a context with higher overall rates of reinforcement (rich contexts) were more persistent than other behaviors that have occurred in a context with relatively lower rates of reinforcement (lean contexts). More surprisingly, behavioral momentum theory goes on to assert that this greater persistence in richer contexts is found even when rate of responding is lower in the rich context, and when the greater richness is due to noncontingent reinforcement or reinforcement for alternative responses. If behavioral momentum effects documented in laboratory settings are manifested in applied settings, these procedures may be used to increase the persistence of desirable behaviors or decrease the rate of problem behavior while simultaneously increasing its persistence. However, research on behavioral momentum has primarily been conducted by basic researchers using basic preparations. A key component of research on behavioral momentum is the presence of different contexts (typically signaled by color cues) each associated with a different rate of reinforcement. It is currently unclear if behavioral momentum effects are common in applied settings and if so, what variables determine context in applied settings. Thus, translational research should be conducted to examine the extent to which behavioral momentum theory accurately predicts behavior in applied settings while making systematic extensions to the established basic procedures. The purpose of the current study was to make one such extension that may be particularly important for replication of behavioral momentum research in applied settings. Two therapists functioned as two contexts with each participant to examine the effects of two interventions (i.e., contingent reinforcement with or without additional noncontingent reinforcement). Across participants, different patterns of results were found. In addition, participant responding was only partially disrupted during extinction and distraction phases, suggesting the procedures did not arrange a strong test of behavioral momentum theory. Because extinction did not reduce responding to very low levels, tests of reinstatement do not allow for clear conclusions to be drawn. In addition, patterns of responding did not clearly indicate participants were discriminating contexts. Several potential reasons for the lack of strong effects are discussed and suggestions for follow-up research are presented.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Meteorology and Physical Oceanography, 1982. / Microfiche copy available in Archives and Science. / Bibliography: leaves 75-77. / by John Roberts Anderson. / M.S.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第17770号 / 理博第3893号 / 新制||理||1561(附属図書館) / 30577 / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 青山 秀明, 教授 畑 浩之, 准教授 早田 次郎 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・論文博士 / 博士(理学) / 乙第12913号 / 論理博第1549号 / 新制||理||1591(附属図書館) / 32123 / 名古屋大学大学院理学研究科 / (主査)准教授 林 泰一, 教授 石川 裕彦, 教授 余田 成男 / 学位規則第4条第2項該当 / Doctor of Science / Kyoto University / DGAM