Nedsiderisiko og aksjeavkastning : En empirisk studie av tapsaversjon blant investorer på Oslo Børs

I denne oppgaven studerer vi hvordan tapsaversjon reflekteres i aksjeavkastning på Oslo Børs. I henhold til teorien om tapsaversjon har investorer asymmetriske risikopreferanser, og bryr seg mer om tap enn de bryr seg om tilsvarende gevinst. Tapsaverse investorer vil følgelig kreve en premie for å holde aktiva med høy nedsiderisiko. Dette er ikke konsistent med kapitalverdimodellen, som tar utgangspunkt i mean-variance nytte, og følgelig antar at investorer har symmetriske risikopreferanser. Vår oppgave er inspirert av studien til Ang et al. (2006), som fant en premie for nedsiderisiko i det amerikanske aksjemarkedet. Hovedformålet med denne oppgaven er å undersøke hvorvidt resultatene fra studien til Ang et al. (2006) er overførbare til det norske aksjemarkedet. Datamaterialet består av daglig aksjeavkastning for alle aksjer på Oslo Børs i perioden fra 1983 til 2020. Vi estimerer nedsiderisikoeksponering og risikopremier ved å benytte Fama-MacBeth regresjonsprosedyren. Vi finner at aksjeavkastningen reflekterer en premie for nedsiderisiko på Oslo Børs. Risikopremien er signifikant når vi kontrollerer for anerkjente risikofaktorer fra litteraturen om verdipapirprising. Blant aksjene med vedvarende høy estimert nedsiderisiko foreligger det en høy konsentrasjon av oljeselskaper. Robusthetstestene våre tilsier imidlertid at premien for nedsiderisiko ikke er relatert til oljepriseksponering, og dermed er relevant for aksjer utenfor oljeindustrien også.In this thesis, we study how loss aversion is reflected in stock returns at the Oslo Stock Exchange. According to theory on loss aversion, investors have asymmetric risk preferences and care more about downside losses than they care about upside gains. Loss averse investors should hence require a premium for holding assets with high downside risk. This is not consistent with the Capital Asset Pricing Model, which is based on mean-variance utility, and hence assumes that investors have symmetric risk preferences. Our thesis is inspired by the study of Ang et al. (2006), who found a premium for downside risk in the U.S. stock market. In this thesis, we investigate whether the results from the study of Ang et al. (2006) are transferrable to the Norwegian stock market. The data material consists of daily stock returns for all stocks on Oslo Stock Exchange in the period from 1983 to 2020. We estimate downside risk exposures and risk premiums using the Fama-MacBeth regression procedure. We find that the stock returns reflect a premium for downside risk on Oslo Stock Exchange. The risk premium is significant when controlling for other well-known risk factors from the asset pricing literature. Among the stocks with persistently high estimated downside risk, there is a high concentration of oil companies. However, our robustness tests suggest that the premium for downside risk is not related to oil price risk exposure, and hence relevant for non-oil stocks as well.nhhma

Low-dose CT coronary angiography for assessment of coronary artery disease in patients with type 2 diabetes - A cross-sectional study

Background Silent coronary artery disease (CAD) is prevalent in type 2 diabetes mellitus (T2DM). Although coronary computed tomography angiography (CCTA) over recent years has emerged a useful tool for assessing and diagnosing CAD it’s role and applicability for patients with T2DM is still unclarified, in particular in asymptomatic patients. We aimed to assess the role of CCTA in detecting and characterizing CAD in patients with T2DM without cardiac symptoms when compared to gold standard invasive coronary angiography (ICA). Methods This was a cross-sectional analysis of patients with T2DM without symptomatic CAD enrolled in the Asker and Baerum Cardiovascular Diabetes Study who, following clinical examination and laboratory assessment, underwent subsequently CCTA and ICA. Results In total 48 Caucasian patients with T2DM (36 men, age 64.0 ± 7.3 years, diabetes duration 14.6 ± 6.4 years, HbA1c 7.4 ± 1.1 %, BMI 29.6 ± 4.3 kg/m2) consented to, and underwent, both procedures (CCTA and ICA). The population was at intermediate cardiovascular risk (mean coronary artery calcium score 269, 75 % treated with antihypertensive therapy). ICA identified a prevalence of silent CAD at 17 % whereas CCTA 35 %. CCTA had a high sensitivity (100 %) and a high negative predictive value (100 %) for detection of patients with CAD when compared to ICA, but the positive predictive value was low (47 %). Conclusions Low-dose CCTA is a reliable method for detection and exclusion of significant CAD in T2DM and thus may be a useful tool for the clinicians. However, a low positive predictive value may limit its usefulness as a screening tool for all CAD asymptomatic patients with T2DM. Further studies should assess the applicability for risk assessment beyond the evaluation of the vascular bed

Determinants and prognostic implications of Cardiac Troponin T measured by a sensitive assay in Type 2 Diabetes Mellitus

<p>Abstract</p> <p>Background</p> <p>The cardiac troponins are biomarkers used for diagnosis of myocardial injury. They are also powerful prognostic markers in many diseases and settings. Recently introduced high-sensitivity assays indicate that chronic cardiac troponin elevations are common in response to cardiovascular (CV) morbidity. Type 2 diabetes mellitus (T2DM) confers a high risk of CV disease, but little is known about chronic cardiac troponin elevations in diabetic subjects. Accordingly, we aimed to understand the prevalence, determinants, and prognostic implications of cardiac troponin T (cTnT) elevations measured with a high-sensitivity assay in patients with T2DM.</p> <p>Methods</p> <p>cTnT was measured in stored, frozen serum samples from 124 subjects enrolled in the Asker and Bærum Cardiovascular Diabetes trial at baseline and at 2-year follow-up, if availabe (96 samples available). Results were analyzed in relation to baseline variables, hospitalizations, and group assignment (multifactorial intensive versus conventional diabetes care for lowering CV risk).</p> <p>Results</p> <p>One-hundred thirteen (90 %) had detectable cTnT at baseline and of those, 22 (18 % of the total population) subjects had values above the 99th percentile for healthy controls (13.5 ng/L). Levels at baseline were associated with conventional CV risk factors (age, renal function, gender). There was a strong correlation between cTnT levels at the two time-points (r = 0.92, p > 0.001). Risk for hospitalizations during follow-up increased step-wise by quartiles of hscTnT measured at baseline (p = 0.058).</p> <p>Conclusions</p> <p>Elevations of cTnT above the 99th percentile measured by a highly sensitive assay were encountered frequently in a population of T2DM patients. cTnT levels appeared to be stable over time and associated with conventional CV risk factors. Although a clear trend was present, no statistically robust associations with adverse outcomes could be found.</p

Potential anti-inflammatory role of activin A in acute coronary syndromes

AbstractObjectivesWe sought to investigate whether activin A could be involved in the immunopathogenesis of acute coronary syndromes.BackgroundInflammatory mechanisms seem to play a pathogenic role in atherosclerosis and acute coronary syndromes, but the actual mediators have not been fully identified. Activin A, a pleiotropic member of the transforming growth factor-beta cytokine family, has recently been suggested to play a role in inflammation.MethodsWe examined the role of activin A and its endogenous inhibitor follistatin in patients with stable (n = 26) and unstable angina (n = 20) and healthy control subjects (n = 20) by different experimental approaches.Results1) Patients with stable angina had raised activin A concentrations, as assessed by protein levels in serum and messenger ribonucleic acid levels in peripheral blood mononuclear cells (PBMCs). 2) Although several activin A–related mediators were upregulated in PBMCs from patients with stable angina compared with controls (i.e., activin A and Smad3), no changes or even downregulation (i.e., Smad2) were seen in unstable disease. 3) The activin type II receptors, representing the primary ligand-binding proteins, were downregulated in unstable compared with stable angina. 4) Percutaneous coronary intervention induced a decrease in the activin A/follistatin ratio, suggesting downregulatory effects on activin A activity. 5) Although activin A dose-dependently suppressed the release of inflammatory cytokines from PBMCs in angina patients, an opposite effect was found in healthy controls.ConclusionsOur findings suggest an anti-inflammatory potential of activin A in angina patients, and such effects may be of particular relevance in unstable angina in which several of the activin parameters were downregulated

The effect of tobacco smoking and treatment strategy on the one-year mortality of patients with acute non-ST-segment elevation myocardial infarction

<p>Abstract</p> <p>Background</p> <p>The aim of the present study was to investigate whether a previously shown survival benefit resulting from routine early invasive management of unselected patients with acute non-ST-segment elevation myocardial infarction (NSTEMI) may differ according to smoking status and age.</p> <p>Methods</p> <p>Post-hoc analysis of a prospective observational cohort study of consecutive patients admitted for NSTEMI in 2003 (conservative strategy cohort [CS]; n = 185) and 2006 (invasive strategy cohort [IS]; n = 200). A strategy for transfer to a high-volume invasive center and routine early invasive management was implemented in 2005. Patients were subdivided into current smokers and non-smokers (including ex-smokers) on admission.</p> <p>Results</p> <p>The one-year mortality rate of smokers was reduced from 37% in the CS to 6% in the IS (p < 0.001), and from 30% to 23% for non-smokers (p = 0.18). Non-smokers were considerably older than smokers (median age 80 vs. 63 years, p < 0.001). The percentage of smokers who underwent revascularization (angioplasty or coronary artery bypass grafting) within 7 days increased from 9% in the CS to 53% in the IS (p < 0.001). The corresponding numbers for non-smokers were 5% and 27% (p < 0.001). There was no interaction between strategy and age (p = 0.25), as opposed to a significant interaction between strategy and smoking status (p = 0.024). Current smoking was an independent predictor of one-year mortality (hazard ratio 2.61, 95% confidence interval 1.43-4.79, p = 0.002).</p> <p>Conclusions</p> <p>The treatment effect of an early invasive strategy in unselected patients with NSTEMI was more pronounced among smokers than non-smokers. The benefit for smokers was not entirely explained by differences in baseline confounders, such as their younger age.</p

Identification and Characterization of Viral Structural Proteins of Infectious Salmon Anemia Virus

Infectious salmon anemia virus (ISAV) is an unclassified Orthomyxovirus that has been shown to contain a segmented genome with eight single-stranded RNA species coding for 10 viral proteins. Four major structural proteins were characterized in the present study: two glycosylated proteins with estimated molecular masses of 42 and 50 kDa, one 66-kDa phosphoprotein, and one 22-kDa protein. Examination of lysed virions revealed the two glycoproteins and the 22-kDa protein in the soluble fraction, while the 66-kDa phosphoprotein and a minor part of the 22-kDa protein were found in the pelleted fraction. Immunofluorescence staining of infected cells demonstrated that the 22-kDa protein was a late protein accumulating in the nucleus. We conclude that the 66-kDa protein is the nucleoprotein, the 22-kDa protein is the matrix protein, and the 42- and 50-kDa proteins are the surface proteins. Radioimmunoprecipitation analysis of the 42-kDa glycoprotein, which was previously shown to represent the ISAV hemagglutinin, indicated that this protein exists at least as dimers. Further, by labeling of purified ISAV with [1,3-(3)H]diisopropyl fluorophosphate, it was also demonstrated that the viral esterase is located with the hemagglutinin. This finding was confirmed by demonstration of acetylesterase activity in affinity-purified hemagglutinin preparations. Finally, the active-site serine residue could be tentatively identified at position 32 within the amino acid sequence of the hemagglutinin of ISAV strain Glesvaer/2/90. It is proposed that the ISAV vp66 protein be termed nucleoprotein, the gp42 protein be termed HE protein, and the vp22 protein be termed matrix protein

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