The odds offered on the presidential election by betting sites are the product of the betting decisions made by individuals putting their money behind their predictions.  They are not a substitute for polling data, but they are an interesting gauge of public opinion on their own, for they reflect a large number of individuals' assessments of what they think their friends and neighbors, as well as strangers, are thinking.  And unlike polls, which take days to carry out and analyze, betting markets move instantaneously with the wagers being placed on them.

As of this morning, two of the seven betting sites included in the Real Clear Politics index of presidential election betting odds have Trump-Biden a dead heat, while the others are close to a tie, but slightly favoring Biden.  For now.

The graph showing changes in the odds over time make it clear that while the odds switched in favor of Biden on June 1,2020, (presumably over voters blaming COVID and associated financial troubles on Trump), that trend has now abated, and the direction of change is in Trump's favor.

Almost certainly, the Republican convention's effectiveness and the complete recovery of the stock market losses that followed the pandemic also had an effect on bettors' perceptions.

But Joe Biden's continued basement sequestration, his weakness in self-presentation, early polls of black support for Trump, and Nancy Pelosi's suggestion that he skip the planned debates must also be sinking in and moving bettors' perceptions of his staying power.

Note that in 2016, the betting markets were no better than the pollsters in predicting the results of that election.  But at least bettors are not influenced by the "shy Trump voter" reticence.