COVID-19 as Information Transmitter to Global Equity Markets: Evidence from CEEMDAN-Based Transfer Entropy Approach

This study provides an analysis of chaotic information transmission from the COVID-19 pandemic to global equity markets in a novel denoised frequency domain entropy framework. The current length of the pandemic data offers the opportunity to examine its role in the asymmetric behaviour patterns of investors according to time horizons and the diversification potentials available to them. We employ the total daily global confirmed cases of COVID-19 and 27 equity indices from December 31, 2019, to April 18, 2021. Our results corroborate the idea that diversification potentials are stronger in the short to medium term. The Global Index (higher risk) and Canada and New Zealand (lower risk) remain at both ends to pair some other equities to offer diversification prospects because of the transmission of information from COVID-19 to the selected equity markets. In addition, we provide the source of these diversification prospects as information flow rather than transmission of shocks, which is common in the literature. Furthermore, our results suggest detailed levels of risk (lower vis-à-vis higher) in the situation where they have been stripped of the noise in the market. The findings allow both investors and policymakers to make informed decisions based on the time horizons since the pandemic communicates different chaotic information with the lapse of time. This is imperative to avoid the negative consequences of the increasing infection rate on global stock markets.

Conclusion

The outbreak of the Covid-19 pandemic in February 2020 led to a spectacular comeback of retail investing in global equity markets. Lockdowns forced millions of people to stay at home, and the suspension of the online sports gambling spirit enticed a new generation of ‘have-a-go investors’ to seek their luck and thrills in the stock market. Financial observers across the board expected the breathtaking surge in retail investing to be a lasting trend and to pose regulatory challenges to the market infrastructure for years to come. The retail stock market frenzy of 2020 and 2021 sparked debates over the place of the ‘amateur’ in the market, the role of social media, and the ‘gamification of investing’. These debates offer an opportunity to hold up a sharp and topical mirror to the historical findings of this book, which in turn may inform future debates about the meaning of retail investing.

COVID-19: A Game-changer to Equity Markets?

This article applies the effective transfer entropy methodology to quantify the information flow between equities in major global equity markets in Australia, Brazil, Canada, China, Germany, Iran, Japan, Qatar, Saudi Arabia, South Africa, South Korea, United Kingdom, and the United States – a pool of 2200 companies included. To account for COVID-19 impacts, the period of the study was extended over two years. The results show changes to the information flow pattern after COVID-19, with the largest changes being encountered in Australia, Brazil, Canada, Japan, and the United States – for their largest market participants (by market capitalization). In comparison, the Asian markets show less noticeable changes in their information flow pattern after COVID-19. On a sector level, most of the markets studied have seen substantial changes in the functionality of their sectors – in terms of being a transmitter or receiver of information – after COVID-19 appearance. The fraction of sectors with a complete change in their influencing role since COVID-19 has been over 70% in Australia, Canada, South Africa, and the United States. The financial services sector has retained its role - as being the most influencing sector - in 6 out of 13 markets considered after COVID-19. For most of the markets, the basic materials, communications, energy, and utilities sectors have retained an intermediate position in the information flow diagram, after COVID-19. The German market has been the only market, in which the main information transmitter and receiver sectors have remained unchanged, since COVID-19. The results suggest drastic moves in major global equity markets, which have been concurrent with the virus outbreak. Doi: 10.28991/HEF-2021-02-01-05 Full Text: PDF