Sentiment, irrationality and market efficiency: The case of the 2010 FIFA World Cup

• The World Cups before 2010 created exploitable abnormal profit.
• This opportunity has become public knowledge just before 2010 World Cup.
• This information changed and shortened the effect.
• This case study shows how sophisticated investors restore market efficiency.

Soccer games create sentiment, which affects stock prices. The World Cups before 2010 provided exploitable abnormal profit which was not exploited, presumably because it was unknown. Just before the 2010 World Cup, the exploitable effect has been discovered and widely cited by practitioners who even suggested recipe how to exploit it. Indeed, the information on the abnormal profit created in 2010 World Cup a price pattern which is different from those corresponding to the previous World Cups. Like other market anomalies, we expect that market efficiency will be restored and this new effect will vanish in the future.