House looks settled; the Senate is the contest
Two chambers, two very different races. In the market, control of the House has drifted toward one side and looks close to settled — the House market currently prices the favoured outcome around 93%. The Senate is where the money is still moving — priced near 8% now, and climbing off its June lows when this was written on 9 July. That gap is the whole story: a chamber the market treats as largely decided, and a chamber it treats as genuinely up for grabs.
Why the Senate is the tighter race
The Senate math is simply harder to move: only a third of seats are up in any cycle, and which specific seats are being defended matters more than the national mood. A party can be favoured for the House and still be an underdog — or a coin-flip — for the Senate, because the two chambers are contested on different maps. A “balance of power” or “sweep” market, currently near 0%, is really a bet that bothchambers break the same way — which is why it prices lower than either chamber alone.