The impact of expected and unexpected events on Bitcoin price development: Introduction of futures market and COVID-19

This study examines the impact of two critical events, the introduction of Bitcoin futures and the COVID-19 pandemic, on Bitcoin's returns and volatility. We find that the inception of Bitcoin futures (positively) impacts its returns in the spot market while no significant interaction occurs for volatilities. The pandemic does not seem to influence Bitcoin's returns or volatility, which is consistent with the notion that Bitcoin is insulated from some global economic developments. Our tests also reveal that Bitcoin spot prices dominate its futures. This information might be useful for investors in capturing trend reversals considering the order of information disseminated. © 2023 Elsevier Inc.

The effect of thrombosis-related laboratory values on mortality in COVID-19 infection.

OBJECTIVE: COVID-19 may cause thrombosis in both venous and arterial systems. Familiarity with the signs and symptoms of thrombosis and its treatment is essential in treating COVID-19 infection and its complications. D-Dimer and mean platelet volume (MPV) are measurements related to the development of thrombosis. This study investigates whether MPV and D-Dimer values could be used to determine the risk of thrombosis and mortality in the COVID-19 early stages. PATIENTS AND METHODS: 424 patients who were COVID-19 positive, according to the World Health Organization (WHO) guidelines, were randomly and retrospectively included in the study. Demographic and clinical characteristics such as age, gender, and length of hospitalization were obtained from the digital records of participants. Participants were divided into living and deceased groups. The patients' biochemical, hormonal, and hematological parameters were analyzed retrospectively. RESULTS: White blood cells (WBC), neutrophils, and monocytes were significantly different in the two groups (p-value <0.001), and their values were lower in the living group than in the deceased group. MPV median values did not differ according to prognosis (p-value = 0.994). While the median value was 9.9 in the survivors, it was 10 in the deceased. Creatinine, procalcitonin, ferritin, and the number of hospitalization days in living patients were significantly lower than in patients who died (p-value <0.001). Median values of D-dimer (mg/L) differ according to prognosis (p-value <0.001). While the median value was 0.63 in the survivors, it was found as 438 in the deceased. CONCLUSIONS: Our results did not show any significant relationship between the mortality of COVID-19 patients and their MPV levels. However, a significant association between D-Dimer and mortality in COVID-19 patients was observed.

Do major health shocks affect the interconnectedness of E-commerce and electronic payment markets? a regional analysis

In view of the recent pandemic and its associated impact, this study examines the relationship between e-commerce and mobile/electronic payment markets by utilizing two indices as proxies of these market developments. The study employed DCC-GARCH modeling, Hacker–Hatemi bootstrap causality test, Diebold–Yilmaz volatility spillover analysis and a volatility modeling incorporating COVID19 related death statistics of three regions: America, Europe and Asia. The results show that while the two markets display very high time-varying correlations across years, a significant causal relationship is only found during the pandemic. Causality runs from the mobile/electronic payment index to the e-commerce index. Volatility spillover analysis further supports this finding. Interestingly, the mobile/electronic payment index tends to become a net volatility transmitter in the pandemic period. When we incorporate regional COVID19 statistics on cases and deaths in the volatility modeling of the e-commerce index, we find that only COVID19 deaths in Europe have a significant effect on e-commerce returns. This result may be rationalized by the relative tightness of the e-commerce market in Europe compared to America and Asia. Likewise, demographic characteristics might be another potential driver for our findings.

Forecast of China’s economic growth during the COVID-19 pandemic: a MIDAS regression analysis

Purpose: This study aims to examine the effect of the COVID-19 pandemic in comparison to the global financial crisis (GFC) on the gross domestic product (GDP) growth rate of China. Design/methodology/approach: Empirical analyses are conducted through alternative methods such as ordinary least squares, Markov regime switching (MRS) and mixed data sampling (MIDAS) regressions. The flexibility of MIDAS regression enables us to use different variables with quarterly (GDP), monthly (export sales and foreign-exchange reserves) and daily frequencies (foreign exchange rates and Brent oil price). Findings: The results indicate that the COVID-19 pandemic has had a considerable negative effect on China’s GDP growth, while the dummy variables used for the GFC are found to be insignificant. Further, the forecast accuracy test statistics exhibited a superior performance from MIDAS regression compared to the alternative models, such as MRS regression analysis. According to the forecast results, the authors expect a recovery in China’s economic growth in the second quarter of 2020. Originality/value: This is one of the earliest studies to examine the effect of the COVID-19 pandemic on the Chinese economy, and to compare the impact of COVID-19 with the GFC. The authors provide further evidence regarding the performance of MIDAS regression analysis vs alternative methods. Findings obtained shed light on policymakers, corporations and households to update their consumption, saving and investment decisions in the chaotic environment of this pandemic. © 2020, Emerald Publishing Limited.

Ventricular repolarization indexes in patients treated with hydroxychloroquine - azithromycin combination for COVID-19.

BACKGROUND: Combination of hydroxychloroquine and azithromycin for the treatment of coronavirus disease 2019 (COVID-19) carries increased risk of corrected QT (QTc) prolongation and cardiac arrhythmias. OBJECTIVE:  To characterize the ventricular repolarization indexes which are associated with malignant ventricular arrhythmias in patients treated with hydroxychloroquine and concomitant azithromycin for COVID-19. METHOD: A total of 81 patients who had hydroxychloroquine and azithromycin combination therapy because of possible or  reverse-transcription polymertase chain reaction (RT-PCR) confirmed diagnosis of COVID-19 were included in the study. Baseline and control electrocardiograms (before and after treatment) were analyzed retrospectively. Tp-e interval, Tp-e/QT and Tp-e/QTc ratios, which are ventricular repolarization indexes, were calculated. RESULTS: While there was no significant increase in QTc interval in patients receiving combination therapy, there was a significant increase in ventricular repolarization indexes. CONCLUSION: The increase in ventricular replarization indexes is associated with the risk of arrhythmia. In patients using QTc prolonging medication for COVID-19 treatment, QTc monitoring alone may not be sufficient to follow-up for arrhythmia. Even if there is no prolongation in QTc, an increase in ventricular repolarization indexes may be seen (Tab. 5, Ref. 37).

Covid-19 pandemic and anxiety related factors in patients treated in the emergency department

Aims: A novel coronavirus, now known as SARS-CoV-2019, suddenly emerged in Wuhan, China and within threemonths of the initial outbreak, the virus had spread rapidly to neighboring countries causing a pandemic. After the first case was announced, emergency departments were immediately reorganized as pandemic clinics. Special areas with maximum precautions were designed to evaluate patients. The majority of studies on this pandemic have focused on the treatment of respiratory symptoms and comorbidities in intensive care units. In this study, we sought to determine those factors that contributed to the anxiety level during the COVID-19 pandemic using the ‘State’ subscale of State-Trait Anxiety Inventory (STAI-S). Methods: A survey was performed in the emergency department by using an online questionnaire which consisted of demographic variables, questions about the opinions and behaviors of patients during the pandemic, diagnostic test results for COVID-19, and treatment methods. Results: There was a statistically significant difference between employment status (p ˂ 0.001), monthly income (p ˂ 0.001), the food consumption changes during the pandemic period (p = 0.001) and the estimated end-date for the COVID-19 pandemic (p < 0.001) and total STAI-S points. Conclusions: Our study has identified factors which significantly increase anxiety during the COVID-19 pandemic and identified those individuals who may benefit from psychiatric and social support.