The PredictIt prediction market has opened markets on the nominees of the Democrat and Republican parties for U.S. president in 2024 as well as the eventual winner of the general election. Current standings (2021-10-20 at 19:47 UTC) are:
Democrat Nominee 3.1 million traded
- Biden 39%
- Harris 30%
- no others above 9%
Republican Nominee 19.4 million traded
- Trump 42%
- DeSantis 22%
- no others above 8%
2024 Presidential Election 188,000 traded
- Trump 29%
- Biden 27%
- DeSantis 18%
- Harris 14%
The way prediction markets work is that you buy shares in Yes or No for your choice at a price of US$1 times the percentage offered in the market. When the event happens and the outcome is known, shares in the correct prediction pay off at par while all others are worthless. So, for example, you could buy 100 shares of Trump president in 2024 for US$ 29 and if he wins the election, you collect US$ 100.
I found the prediction of Biden as the Democrat nominee surprisingly low.