US Senate Election Odds

Senate markets come in three layers, and confusing them is the most common mistake made reading a political board. The control contract prices which party holds the chamber. A seat contract prices one state. A primary or nominee contract prices who gets on the ballot in the first place. All three are on this page, quoted across every platform listing them.

Control is the liquid one, and it is arithmetically tied to a handful of seats. With only a third of the chamber up in any cycle and most of those seats safe, control usually turns on four to six genuinely competitive states. That makes the relationship checkable: if the competitive seat prices imply a party is comfortably favoured while the control market is near a coin flip, one of the two is wrong, and the discrepancy is visible on this board because both are priced here at once.

Primaries deserve separate attention. In a safe state the primary is the election, and those contracts routinely trade at a fraction of the volume of the general - which means they are the ones most likely to be stale on one venue while another has already repriced. Nominee fields also carry many contracts simultaneously, so the sum of every candidate is a live read on how much of the field the market still considers open.

Senate contracts move on candidate-level news more than any other federal market: a retirement, a recruitment, a primary challenge from the flank, a health story. Those events are discrete and dateless, which is why a Senate board can sit flat for weeks and then reprice twenty points in an afternoon. Prices here refresh at least once a minute, so the move shows up before the commentary does.