Using the financial event study methodology, this research analyzed how various US economic sectors and industry groups responded to a major Covid-19 vaccine announcement. The results indicate that equities in the Energy, Industrials, Consumer Cyclicals, Financials, Real Estate, Technology, and Academic and Educational Services US economic sectors experienced various magnitudes of positive abnormal returns during the event period. This research thus provided empirical evidence of how Covid-19 vaccine announcements have influenced US equity returns.

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