Our study aimed to determine the effects of new-onset neurological symptoms (NNS) on clinically relevant outcomes in hospitalized patients with COVID-19 infection. We conducted a nationwide, comparative, retrospective, cohort study among adult, hospitalized COVID-19 patients involving 37 hospital sites from various regions in the Philippines. We included a total of 10,881 patients with confirmed COVID-19 infection (2008 had NNS while 8873 did not have NNS). The adjusted hazard ratios (aHRs) for mortality among the mild and severe cases were significantly higher by 1.660 (95% CI 1.132–2.435) and by 1.352 (95% CI 1.042–1.752), respectively, in the NNS group compared to those in the non-NNS group. The aHRs for respiratory failure in the NNS group were significantly increased by 1.914 (95% CI 1.346–2.722), by 1.614 (95% CI 1.260–2.068), and by 1.234 (95% CI 1.089–1.398) among the mild, severe, and critical cases, respectively. The aHRs for ICU admission in the NNS group were still significantly higher by 1.973 (95% CI 1.457–2.673) and by 1.831 (95% CI 1.506–2.226) among the mild and severe cases, respectively. Patients who had NNS were not significantly associated with a longer duration of ventilator dependence (adjusted odds ratio (aOR) 0.954, 95% CI 0.772–1.179), longer ICU stay (aOR 0.983, 95% CI 0.772–1.252) and longer hospital admission (aOR 1.045, 95% CI 0.947–1.153). The presence of NNS significantly increases the risk of mortality, respiratory failure and ICU admission among COVID-19 patients. Registration and associated protocol publication: ClinicalTrials.gov website (NCT04386083); Espiritu AI, Sy MCC, Anlacan VMM, Jamora RDG. The Philippine COVID-19 Outcomes: a Retrospective study Of Neurological manifestations and Associated symptoms (The Philippine CORONA study): a protocol study. BMJ Open. 2020;10:e040944.

This essay aims to analyse the impact of the 2020 global pandemic on the stock indexes of France (CAC 40), Germany (DAX 30), USA (DOW JONES), United Kingdom (FTSE 100), Italy (FTSE MID), Japan (Nikkei 225) and Canada (TSX 300), from January 2018 to June 2020, with the sample being divided into two sub periods: first sub period from January 2018 to August 2019 (Pre-Covid); second period from September 2019 to June 2020 (Covid-19). In order to carry out this analysis, different approaches were taken in order to analyse whether: (i) the global pandemic (Covid-19) increased the persistence of the G7 financial markets? In the Pre-Covid period, we can verify the presence of long memories in the Canadian market (TSX), while the markets in France (CAC 40) and Italy (FTSE MID) show signs of balance, since the random walk hypothesis was not rejected. The German (DAX 30), USA (DJI), United Kingdom (FTSE 100) and Japan (NIKKEI 225) markets have anti-persistence (0 <α <0.5). In period II, the Covid-19-time scale is contained, and we verified the presence of significant long memories, except for the US stock index (0.49). These findings make it possible to show that the assumption of the market efficiency hypothesis may be called into question, because these markets are predictable, which validate the research question. The results of the pDCCA correlation coefficients, in the Pre-Covid period, show 14 pairs of median markets (0.333 → ≌ 0.666). We can also see 7 pairs of markets with strong correlation coefficients (0.666 → ≌ 1,000), showing that these markets have a tendency towards integration, this evidence may call into question the hypothesis of portfolio diversification. In period II (Covid-19) the λ_DCCA correlation coefficients have 7 strong market pairs (0.666 → ≌ 1,000), 5 pairs have weak pDCCA coefficient (0.000 → ≌ 0.333), 5 market pairs show anti-correlation (-1.000 → ≌ 0.000), and 4 market pairs show median coefficients (pDCCA) (0.333 → ≌ 0.666) (out of 21 possible). When compared to the previous subperiod, we found that the majority of the pDCCAs decreased, which shows that the markets have decreased their integration, making it possible to diversify portfolios in certain markets, especially in the Japanese market (NIKKEI 225). These conclusions open space for market regulators to take measures to ensure better informational information, in the stock markets, in the 7 most advanced economies in the world.

The pandemic outbreak (Covid-19) has affected the global economy, and the impact on financial markets seems inevitable. In view of these events, this essay intends to analyse the efficiency, in its weak form, in the BRIC markets, namely the stock indexes of Brazil (BRAZIL IBOVESPA), China (Shanghai Stock Exchange), India (S&P BSE SENSEX), Russia (MOEX Russia). The data are intraday (1 hour), from May 2019 to May 2020; to obtain more robust results, we divided the sample into time scales up to 5 days (Period I), and above 10 days (Period II), in a complementary way, and we use the opening and closing prices to estimate the adjustment time of each market. The results indicate that the BRIC markets have significant persistence (over 10 days), which may jeopardize market efficiency, in its weak form. On the other hand, the low initial correlation in certain stock indexes may create some arbitrage opportunities. However, our study did not analyse anomalous meturns in these financial markets. These conclusions also open space for market regulators to take measures to ensure better information between these markets and international ones.

The Efficient Market Hypothesis (EMH), is one of the most important hypotheses in the financial economy, which argues that yields have no memory (correlation), which implies that agents cannot have abnormal returns in the financial markets, base arbitration operations. This essay intends to investigate the efficiency, in its weak form, in the stock and bond markets of Portugal and EDP, in the period from December 31, 2019, to August 10, 2020. With the purpose of achieving such an analysis, whether: (i) with the evolution of the global pandemic (Covid-19) the Portuguese and EDP stock and bond markets show signs of (in) efficiency? (ii) Does the increased integration between the Portuguese and EDP stock and bond markets result in risk transmission? The model 𝐷𝐹𝐴 shows the existence of long memories in these markets, suggesting that they are not efficient, which validates the first research question. This situation has implications for investors, since some returns can be expected, creating opportunities for arbitrage and abnormal earnings. However, to confirm the inefficiency of these markets, based on our results, we must prove the existence of anomalous returns. In order to answer the second investigation question, we carried out the integration test that shows that these markets are mostly integrated. To validate whether financial integration results in risk transmission between the analyzed markets, we estimate the trendless cross-correlation coefficients (𝜆𝐷𝐶𝐶𝐴), which shows 4 pairs of markets showing risk transmission (4 out of 10 possible). In conclusion, the authors suggest that these results are of interest, among others, to international investors interested in expanding the geographical scope, regarding the implementation of portfolio diversification strategies.