The corona virus 2019 (COVID 19) pandemic has impacted businesses differently with many industries recording negative trends. Travel restrictions are seen as a solution to contain the spread of the virus, and these have impacted operations in the airline industry. This research uses an Events Study approach to investigate if the efficient market hypothesis holds for the airline industrystocks, following the announcements of three COVID 19 related events: declaration of COVID 19 a global pandemic; announcement of financial relief packages; and announcement of vaccination rollout. Using a sample of 46 airline stocks in 10 countries, empirical results suggest that the efficient market hypothesis does not hold when there is excessive information flowing in the market and that events with confounding effect lead to semi-efficient market hypothesis.