Market Efficiency: The Efficiency of Online Sportsbooks in the NHL Betting Market

We investigate the efficiency of various legalized, online sportsbooks in the National Hockey League betting market. Empirical research, across several sports, find that betting markets tend to be efficient. However, there have been recognized inefficiencies in several sports, but over time, these inefficiencies tend to dissipate. Sports betting has increased dramatically as betting has been legalized in an increasing number of states. With the increase in the number of states legalizing online sports betting, the increase in the availability of online sports books, and the growing interest and participation in online sports betting, the question of interest becomes are these various online sportsbooks efficient in the online betting market. We test the efficiency of twelve different online sportsbooks that have posted odds for NHL hockey games starting with the 2018-2019 season through the 2021-2022 season. Out of the twelve sportsbooks that we tested, we found that only three sportsbooks were inefficient at the 10% significance level over this period. We also find that the results are dominated by the 2021-2022 regular season.