Of course, ticket sales are deeply affected by the fact that not all theaters in America are currently open (major markets like Los Angeles, New York, and San Francisco are still keeping them closed) and those in operation around the country are working with limited capacity audiences in promotion of health and safety.
Per Variety, Tenet made only $6.7 million during its second Friday-to-Sunday, which calculates to a 66.5 percent drop from weekend to weekend (though the trade notes that the film actually only made an estimated $9 million in the same three day time span last week, as the $20 million figure came from including Thursday previews and Labor Day holiday estimates).