PREDICTWIRE · LIVEGavin Newsom win the 2028 Democratic presidential nomination: 28% ▲ 0.4Atletico Madrid win the 2025–26 Champions League: 12% ▼ 0.2the San Antonio Spurs win the 2026 NBA Finals: 15% ▲ 0.1Iran x Israel/US conflict ends by April 7: 87% ▲ 0.8Gavin Newsom win the 2028 US Presidential Election: 17%Netherlands win the 2026 FIFA World Cup: 3% ▼ 0.1the Colorado Avalanche win the 2026 NHL Stanley Cup: 23% ▲ 1.1J.D. Vance win the 2028 Republican presidential nomination: 39% ▲ 0.8the U.S. invade Iran before 2027: 30% ▼ 2.0PREDICTWIRE · LIVEGavin Newsom win the 2028 Democratic presidential nomination: 28% ▲ 0.4Atletico Madrid win the 2025–26 Champions League: 12% ▼ 0.2the San Antonio Spurs win the 2026 NBA Finals: 15% ▲ 0.1Iran x Israel/US conflict ends by April 7: 87% ▲ 0.8Gavin Newsom win the 2028 US Presidential Election: 17%Netherlands win the 2026 FIFA World Cup: 3% ▼ 0.1the Colorado Avalanche win the 2026 NHL Stanley Cup: 23% ▲ 1.1J.D. Vance win the 2028 Republican presidential nomination: 39% ▲ 0.8the U.S. invade Iran before 2027: 30% ▼ 2.0

Case Study: Will Kamala Harris win the 2024 US Presidential Election? — How Polymarket’s Price Moved

Resolved case study · Iconic Markets

Will Kamala Harris win the 2024 US Presidential Election?

Resolved No at 43.5% after $1037.0M in trading volume.
Brier score 0.1892. Other category.

What is this?
A resolved Polymarket contract from our archive. We replay the Wire Score against the price at close and at the midpoint, then show what Wire would have called and how that call paid off.

The bottom line
The market got directionally correct but paid a non-trivial price for uncertainty.

Receipt · Wire at close

What Wire called vs. what happened

CALIBRATED
Wire called the price CALIBRATED at close (signal 48). The market resolved NO.
Closing price
42.1%
market at resolution

Wire point
41.2%
calibrated read

Wire Signal
48
CALIBRATED

Outcome
No
Brier 0.1892

Price trajectory

How the market moved over 306 snapshots

Five checkpoints across the contract’s life. Full daily-snapshot range: 0.7–53.9%.

Checkpoint Date Yes price
Start Jan 06, 2024 3.1%
25% in Mar 22, 2024 1.6%
Halfway Jun 06, 2024 1.8%
75% in Aug 21, 2024 48.1%
Close Nov 06, 2024 42.1%
At close

Wire Score detail

Closing market price 42.1%
Wire Score point 41.2%
Confidence band (C) 30.4–52.0%
Grade C
Wire Signal 48 · CALIBRATED
Actual outcome No
Brier score 0.1892
Mid-life snapshot · Jun 07, 2024

What Wire would have said halfway through

Not a live forecast — a backward-looking illustration of what the Wire Score would have produced at this midpoint, using only information available then.

Market price 1.5%
Wire Score point 2.0%
Confidence band (A) 1.2–2.8%
Grade A
Wire Signal 52 · CALIBRATED
Wire’s side YES
$100 on Wire’s side → realized P&L $-100
Archive context

What the archive says about markets like this

This market is one of 1,914 resolved binary contracts in the PredictWire Calibration Archive. A Polymarket contract with lifetime volume of $1037.0M sits in the top tier of archive volume — very liquid markets have a volume-weighted Brier of 0.0665 across the archive, compared to 0.0865 for the full set. Liquidity matters for calibration.

The Wire Score framework uses every (price, outcome) pair in the archive to calibrate raw prices into probabilities and to assign a letter grade based on confidence-band width. v2 fits a separate calibration curve per category (politics, sports, crypto, geopolitics, other) and falls back to a global curve when a category is too thin. Across all 194,111 archive snapshots, Wire Score v2 improves Brier by +4.86% over raw prices (and +2.85% over v1) while remaining monotone across grades.

About this page. Written and reviewed by The PredictWire Research Team under our Editorial Standards. Price data from Polymarket’s public CLOB; outcome data from Polymarket’s gamma-api. Methodology: /wire-score/. Last reviewed April 21, 2026. Corrections: corrections@predictwire.io.