Forecasting stock market volatility and the informational efficiency of the DAX-index options market

Alternative strategies for predicting stock market volatility are examined. In out-of-sample forecasting experiments implied-volatility information, derived from contemporaneously observed option prices or history-based volatility predictors, such as GARCH models, are investigated, to determine if they are more appropriate for predicting future return volatility. Employing German DAX-index return data it is found that past returns do not contain useful information beyond the volatility expectations already reflected in option prices. This supports the efficient market hypothesis for the DAX-index options market

Forecasting stock market volatility and the informational efficiency of the DAX-index options market

SIGLEAvailable from Bibliothek des Instituts fuer Weltwirtschaft, ZBW, Duesternbrook Weg 120, D-24105 Kiel W 124 (100) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Culprit vessel–only versus multivessel percutaneous coronary intervention in patients with cardiogenic shock complicating ST-segment–elevation myocardial infarction

Background The optimal revascularization strategy in patients with multivessel disease presenting with cardiogenic shock complicating ST-segment-elevation myocardial infarction remains unknown. Methods and Results Databases were searched from 1999 to October 2016. Studies comparing immediate/single-stage multivessel percutaneous coronary intervention (MV-PCI) versus culprit vessel-only PCI (CO-PCI) in patients with multivessel disease, ST-segment-elevation myocardial infarction, and cardiogenic shock were included. Primary end point was short-term (in-hospital or 30 days) mortality. Secondary end points included long-term mortality, cardiovascular death, reinfarction, and repeat revascularization. Safety end points were in-hospital stroke, renal failure, and major bleeding. The meta-analysis included 11 nonrandomized studies and 5850 patients (1157 MV-PCI and 4693 CO-PCI). There was no significant difference in short-term mortality with MV-PCI versus CO-PCI (odds ratio [OR], 1.08; 95% confidence interval [CI], 0.81-1.43; P=0.61). Similarly, there were no significant differences in long-term mortality (OR, 0.84; 95% CI, 0.54-1.30; P=0.43), cardiovascular death (OR, 0.72; 95% CI, 0.42-1.23; P=0.23), reinfarction (OR, 1.65; 95% CI, 0.84-3.26; P=0.15), or repeat revascularization (OR, 1.13; 95% CI, 0.76-1.69; P=0.54) between the 2 groups. There was a nonsignificant trend toward higher in-hospital stroke (OR, 1.64; 95% CI, 0.98-2.72; P=0.06) and renal failure (OR, 1.30; 95% CI, 0.98-1.72; P=0.06), with no difference in major bleeding (OR, 1.47; 95% CI, 0.39-5.63; P=0.57) with MV-PCI when compared with CO-PCI. Conclusions This meta-analysis of nonrandomized studies suggests that in patients with cardiogenic shock complicating ST-segment-elevation myocardial infarction, there may be no significant benefit with single-stage MV-PCI compared with CO-PCI. Given the limitations of observational data, randomized trials are needed to determine the role of MV-PCI in this settin