This question has been settled with a final result: "Only after vaccination". Trading has finished.
"I believe that humanity will beat this pandemic, but only when most of the population is vaccinated. Until then, life will not return to normal. [...] Sports will be played in basically empty stadiums." [1]
We generously define 'a basically empty stadium' as one only half full, i.e. at less than 50% of capacity. We look at football stadiums, as football is the most popular sport in the USA.
Comparing the 2020 NFL attendance numbers to the 2019 average, crowds are only about 30% of the previous years.[2]
[1] The Economist - "The world after covid-19. Bill Gates on how to fight future pandemics" by Bill Gates. 23 Apr. 2020
[2] ESPN - "NFL Attendance 2019 & 2020"