The Profitability of Using Pegged Currencies in Carry Trade: A Case of Saudi Riyal

This paper examines the profitability of using pegged currencies in carry trade. Conducting this exercise on Saudi riyal against six floating currencies has proven to be very rewarding especially when enhanced with forecasting methods. Carry trade is a very popular currency speculation strategy among traders, where they borrow low-interest currencies and invest in high-interest currencies. It is a strategy that takes advantage of interest rate differentials between two currencies. Such strategy should not work under uncovered interest parity (UIP), since according to UIP high interest rate currencies should depreciate against low interest rate currencies by the interest rate differential itself. But studies have shown that UIP does not stand and carry traders are profiting from it. As a result of its failure, carry traders are making returns matching the returns of the S&P 500 and outperforming it in terms of the Sharpe ratio

SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

Background: Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods: The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18-49, 50-69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results: NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion: As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population