Kalshi, PredictIt (faintly) see a new Supreme Court Justice in 2022

With it looking increasingly likely that Republicans will control the Senate after the 2022 midterm elections, Democrats are stepping up pressure on Justice Stephen Breyer to retire while their party retains a slim majority (51-50) in the U.S. Senate.

As of January 13th, both PredictIt (Yes: $0.56) and Kalshi (Yes: $0.52) traders think it’s slightly likely that a new Supreme Court Justice is confirmed in 2022.

PredictIt is a prediction market while Kalshi is an exchange for event contracts.  Both markets operate with similar rules, but have a few very important distinctions:

  • PredictIt limits the number of traders per market and the amount a trader can invest in a single contract.  No controls on inside information.
  • Kalshi is federally regulated, and insider trading is prohibited.  No limits on traders or investments.

The Kalshi SCOTUS market (December 2nd) is slightly older than PredictIt’s market (December 17th.)  PredictIt has had 28,786 shares trades, and while Kalshi changed the way it calculates volume over Christmas, it has $17,583 worth of shares traded so it is probably safe to assume Kalshi has a larger volume traded.

Kalshi theoretically has more traders than PredictIt, while PredictIt theoretically has more knowledgeable traders (with the ability to use inside information.)

It’s important to note that both markets don’t specify that Justice Stephen Breyer retires, or even how a vacancy is created, only that the U.S. Senate confirms a new justice before the end of 2022.  It is rare in recent history for a Supreme Court Justice to die on the bench; between 1950 and 2015 only two Justices passed away while serving (Vinson, Rehnquist).  However, since 2016 two of the three vacancies have come from Justices dying (Scalia, Ginsburg) rather than retiring (Kennedy) from the bench.