# Who will win 2027 Chicago mayoral election

> Alexi Giannoulias leads at 55%, runner-up 20% across 4 winner-take-all outcomes — refreshed 15 min ago.

URL: https://simplefunctions.dev/odds/chicagomayor
Updated: 2026-06-26T10:20:51.253Z
Category: politics · Topic: election-2026
Status: active
Closes: 2028-02-23

## Headline

- Leader: Alexi Giannoulias at 55%
- Runner-up: Susana Mendoza at 20%
- Outcomes: 4 (winner-take-all)
- Venue: Kalshi (4 contracts)
- 24h volume: $1K

## Bound contracts (4)

| Outcome | Price | 24h | Volume | Venue | Slug |
|---|---|---|---|---|---|
| Alexi Giannoulias | 55¢ | +1pp | $68 | kalshi | /markets/who-will-win-2027-chicago-mayoral-election-alexi-g-kalshi-kxchicagomayor-27-agia |
| Susana Mendoza | 20¢ | −3pp | $145 | kalshi | /markets/who-will-win-2027-chicago-mayoral-election-susana-kalshi-kxchicagomayor-27-smen |
| Matt Brewer | 13¢ | — | $914 | kalshi | /markets/who-will-win-2027-chicago-mayoral-election-matt-br-kalshi-kxchicagomayor-27-mbre |
| Brandon Johnson | 8¢ | −2pp | $0 | kalshi | /markets/who-will-win-2027-chicago-mayoral-election-brandon-kalshi-kxchicagomayor-27-bjoh |

## 30-day trajectory

| Day | Alexi Giannoulias | Susana Mendoza | Matt Brewer |
|---|---|---|---|
| 2026-05-27 | — | 13 | — |
| 2026-05-29 | 53 | 14 | — |
| 2026-06-11 | 51 | 26 | — |
| 2026-06-12 | 52 | — | — |
| 2026-06-18 | 53 | 26 | — |
| 2026-06-25 | 56 | 22 | 9 |

_17 days of price history captured. Each row is the daily mean of intraday 5-min captures._

## What moved the line

- 2026-06-25 · Susana Mendoza −3pp 25→22¢ · kalshi

## Analysis

The 53% probability indicates that market participants currently view the leader as having a slight majority chance of winning Chicago's 2027 mayoral election, with the runner-up at 15% and remaining candidates sharing the balance. This level reflects relatively limited trading volume across four contracts, suggesting modest market confidence rather than consensus. The probability would likely shift based on changes in polling data, endorsements from major political figures, or shifts in campaign fundraising. The primary catalyst for uncertainty resolution will be the election itself in 2027, though interim developments—such as early primary results, candidate withdrawals, or major policy announcements—could meaningfully move prices before then. Current trading volume of approximately $125,447 in the 24-hour window suggests moderate but not intense market interest in this outcome.

### Key factors

- Current leader holds 53% probability with only 15% for runner-up, indicating meaningful but not overwhelming market conviction
- Four-contract market structure with limited 24-hour volume suggests relatively low liquidity and potential for sharp repricing on new information
- No near-term scheduled events specified; major catalysts likely include campaign announcements, polling data releases, and primary election dynamics over the next 18+ months
- Market is pricing this roughly 18+ months before the election occurs, creating substantial time for candidate positioning, coalition-building, and political developments to shift expectations
- Price reflects early-stage speculation with incomplete information about final candidate field and campaign dynamics

## Methodology

Headline is the **leader's price**, not an arithmetic mean — averaging disjoint winner-take-all outcomes is meaningless. Per-outcome prices come from the venue's last-traded mid; cross-venue values are simple means across contracts on each venue.

## How to use this data

- HTML: https://simplefunctions.dev/odds/chicagomayor
- JSON: https://simplefunctions.dev/api/public/odds?slug=chicagomayor
- Topic hub: https://simplefunctions.dev/predictions/election-2026

## License

CC-BY-4.0. Attribute "SimpleFunctions" with a link to https://simplefunctions.dev. See https://simplefunctions.dev/legal for terms.