Prediction Markets 2028 Democratic Presidential Nominee

2028 Democratic Presidential Nominee Odds

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Updated 59 minutes ago · 12:59 AM PDT

Gavin Newsom leads the 2028 Democratic nomination at 26.3%, holding frontrunner status off a February book tour that doubled as a campaign prelude and a Guardian quote about "stepping into that void" if no one else brings the fire. Alexandria Ocasio-Cortez has a 8.8% chance, still weighing a presidential run against a 2028 Senate primary challenge to Chuck Schumer. Kamala Harris rounds out the top three at 7.8% after a recent rally in Augusta where he tore into the "Mar-a-Lago Mafia" over the Iran war, affordability, and corruption. DeFi Rate's custom odds tracker blends live pricing from Kalshi, Polymarket, and Forecastex into a single consensus probability, refreshed hourly.

Largest Spread

2.21%

Jon Ossoff → View arbs

Current Favorite

26.3%

Gavin Newsom 8.5%

24H Volume (Share)

$1.6M

Momentum Leader

+3.9%

Kamala Harris YTD change

Current Odds Snapshot

Current probabilities across platforms with liquidity indicators

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Gavin Newsom

Vol $55.5K Spread 50.5%

Agg 26.3%

↓ -8.5%

California Governor

F 76.0%

P 26.7%

K 25.5%

ForecastEx 76.0%

Vol $0 76¢

Polymarket 26.7%

Vol $39.9K 26.6–26.7¢

Kalshi 25.5%

Vol $15.6K 25–26¢

AOC

Alexandria Ocasio-Cortez

Vol $5.8K Spread 1.5%

Agg 8.8%

↓ -3.6%

NY Representative

F 10.0%

K 9.5%

P 8.6%

ForecastEx 10.0%

Vol $0 10¢

Kalshi 9.5%

Vol $1.7K 9.4–9.5¢

Polymarket 8.6%

Vol $4.1K 8.5–8.6¢

Kamala Harris

Vol $7.3K Spread 3.5%

Agg 7.8%

↑ +3.9%

F 11.0%

K 7.9%

P 7.6%

ForecastEx 11.0%

Vol $0 11¢

Kalshi 7.9%

Vol $5.2K 7.8–7.9¢

Polymarket 7.6%

Vol $2.1K 7.5–7.6¢

Jon Ossoff

Vol $12.2K Spread 2.4%

Agg 6.7%

↑ +3.1%

K 9.0%

P 6.6%

Kalshi 9.0%

Vol $896 8.9–9¢

Polymarket 6.6%

Vol $11.3K 6.5–6.6¢

Pete Buttigieg

Vol $8.3K Spread 3.8%

Agg 4.4%

↓ -0.3%

F 8.0%

K 5.6%

P 4.3%

ForecastEx 8.0%

Vol $0 8¢

Kalshi 5.6%

Vol $641 5.5–5.6¢

Polymarket 4.3%

Vol $7.7K 4.2–4.3¢

Josh Shapiro

Vol $4.6K Spread 4.9%

Agg 4.1%

↓ -1.3%

F 9.0%

K 5.4%

P 4.1%

ForecastEx 9.0%

Vol $0 9¢

Kalshi 5.4%

Vol $302 5.3–5.4¢

Polymarket 4.1%

Vol $4.3K 4–4.1¢

Mark Kelly

Vol $7.5K Spread 1.2%

Agg 2.9%

↑ +1.0%

K 3.9%

P 2.7%

Kalshi 3.9%

Vol $1.4K 3.8–3.9¢

Polymarket 2.7%

Vol $6.0K 2.6–2.7¢

Andy Beshear

Vol $7.6K Spread 6.5%

Agg 2.8%

↓ -2.0%

F 9.0%

K 4.0%

P 2.6%

ForecastEx 9.0%

Vol $0 9¢

Kalshi 4.0%

Vol $1.4K 3.9–4¢

Polymarket 2.6%

Vol $6.2K 2.5–2.6¢

Rahm Emanuel

Vol $13.9K Spread 1.3%

Agg 2.8%

↑ +0.8%

K 3.7%

P 2.4%

Kalshi 3.7%

Vol $4.7K 3.6–3.7¢

Polymarket 2.4%

Vol $9.3K 2.3–2.4¢

James Talarico

Vol $48 Spread —

Agg 2.4%

↑ +1.9%

K 2.4%

Kalshi 2.4%

Vol $48 2.3–2.5¢

Jon Stewart

Vol $87.5K Spread 1.0%

Agg 2.2%

↑ +1.4%

Comedian

P 2.3%

K 1.2%

Polymarket 2.3%

Vol $87.3K 2.2–2.3¢

Kalshi 1.2%

Vol $229 1.1–1.3¢

JBP

J.B. Pritzker

Vol $21.1K Spread 2.1%

Agg 2.0%

↓ -0.2%

F 4.0%

K 2.9%

P 2.0%

ForecastEx 4.0%

Vol $0 4¢

Kalshi 2.9%

Vol $1.1K 2.9–3¢

Polymarket 2.0%

Vol $19.9K 1.9–2¢

Ro Khanna

Vol $26.6K Spread 1.1%

Agg 2.0%

↑ +0.7%

K 3.1%

P 2.0%

Kalshi 3.1%

Vol $309 3–3.1¢

Polymarket 2.0%

Vol $26.2K 1.9–2¢

Gretchen Whitmer

Vol $27.1K Spread 2.7%

Agg 1.4%

↓ -3.2%

F 4.0%

K 1.4%

P 1.4%

ForecastEx 4.0%

Vol $0 4¢

Kalshi 1.4%

Vol $43 1.3–1.4¢

Polymarket 1.4%

Vol $27.1K 1.3–1.4¢

Wes Moore

Vol $20.2K Spread 3.8%

Agg 1.3%

↓ -1.2%

F 5.0%

K 2.0%

P 1.3%

ForecastEx 5.0%

Vol $0 5¢

Kalshi 2.0%

Vol $801 1.9–2.1¢

Polymarket 1.3%

Vol $19.4K 1.2–1.3¢

Roy Cooper

Vol $10.7K Spread 0.7%

Agg 1.2%

↑ +0.5%

P 1.2%

K 0.4%

Polymarket 1.2%

Vol $10.7K 1.1–1.2¢

Kalshi 0.4%

Vol $0 0.4–0.5¢

Michelle Obama

Vol $30.5K Spread 0.2%

Agg 1.1%

↑ +0.1%

K 1.3%

P 1.1%

Kalshi 1.3%

Vol $9 1.2–1.4¢

Polymarket 1.1%

Vol $30.5K 1–1.1¢

John Fetterman

Vol $19.5K Spread 0.9%

Agg 1.0%

↓ -0.2%

P 1.1%

K 0.2%

Polymarket 1.1%

Vol $19.5K 1–1.1¢

Kalshi 0.2%

Vol $3 0.1–0.2¢

SAS

Stephen A. Smith

Vol $14.7K Spread 0.5%

Agg 1.0%

↑ +0.1%

P 1.1%

K 0.5%

Polymarket 1.1%

Vol $14.7K 1–1.1¢

Kalshi 0.5%

Vol $50 0.5–0.6¢

Dwayne Johnson

Vol $44.3K Spread 0.8%

Agg 1.0%

↓ -0.2%

P 1.1%

K 0.3%

Polymarket 1.1%

Vol $44.1K 1–1.1¢

Kalshi 0.3%

Vol $195 0.2–0.3¢

Chelsea Clinton

Vol $148.2K Spread —

Agg 1.0%

↑ +0.4%

P 1.0%

Polymarket 1.0%

Vol $148.2K 0.9–1¢

Mark Cuban

Vol $12.0K Spread 0.2%

Agg 1.0%

↑ +0.2%

P 1.0%

K 0.8%

Polymarket 1.0%

Vol $12.0K 0.9–1¢

Kalshi 0.8%

Vol $0 0.7–0.8¢

Cory Booker

Vol $14.2K Spread 0.2%

Agg 0.9%

↑ +0.2%

P 1.0%

K 0.8%

Polymarket 1.0%

Vol $14.2K 0.9–1¢

Kalshi 0.8%

Vol $25 0.7–0.8¢

Elissa Slotkin

Vol $3 Spread —

Agg 0.8%

↑ +0.3%

K 0.8%

Kalshi 0.8%

Vol $3 0.7–0.9¢

Barack Obama

Vol $26.8K Spread 0.5%

Agg 0.8%

↑ +0.1%

P 0.8%

K 0.3%

Polymarket 0.8%

Vol $26.8K 0.7–0.8¢

Kalshi 0.3%

Vol $0 0.2–0.3¢

Jared Polis

Vol $21.9K Spread 0.3%

Agg 0.8%

↓ -0.2%

P 0.8%

K 0.4%

Polymarket 0.8%

Vol $21.9K 0.7–0.8¢

Kalshi 0.4%

Vol $0 0.4–0.5¢

MrBeast

Vol $33.8K Spread —

Agg 0.8%

↑ +0.2%

P 0.8%

Polymarket 0.8%

Vol $33.8K 0.7–0.8¢

Raphael Warnock

Vol $15.2K Spread 0.3%

Agg 0.8%

↑ +0.2%

P 0.8%

K 0.4%

Polymarket 0.8%

Vol $15.2K 0.7–0.8¢

Kalshi 0.4%

Vol $1 0.4–0.5¢

Ruben Gallego

Vol $71.0K Spread 0.0%

Agg 0.8%

↓ -0.3%

K 0.8%

P 0.8%

Kalshi 0.8%

Vol $0 0.7–0.8¢

Polymarket 0.8%

Vol $71.0K 0.7–0.8¢

Lebron James

Vol $25.2K Spread 0.7%

Agg 0.7%

↓ -0.1%

P 0.8%

K 0.1%

Polymarket 0.8%

Vol $25.2K 0.7–0.8¢

Kalshi 0.1%

Vol $4 0–0.1¢

Liz Cheney

Vol $27.7K Spread 0.7%

Agg 0.7%

↑ +0.2%

P 0.8%

K 0.1%

Polymarket 0.8%

Vol $27.7K 0.7–0.8¢

Kalshi 0.1%

Vol $5 0–0.1¢

Andrew Yang

Vol $17.2K Spread —

Agg 0.7%

↑ +0.1%

P 0.7%

Polymarket 0.7%

Vol $17.2K 0.6–0.7¢

BOR

Beto O’Rourke

Vol $39.0K Spread —

Agg 0.7%

↓ -0.2%

P 0.7%

Polymarket 0.7%

Vol $39.0K 0.6–0.7¢

Chris Murphy

Vol $154.3K Spread 0.1%

Agg 0.7%

— +0.0%

P 0.7%

K 0.5%

Polymarket 0.7%

Vol $154.3K 0.6–0.7¢

Kalshi 0.5%

Vol $0 0.5–0.6¢

George Clooney

Vol $19.4K Spread —

Agg 0.7%

↑ +0.1%

P 0.7%

Polymarket 0.7%

Vol $19.4K 0.6–0.7¢

Hilary Clinton

Vol $44.1K Spread 0.5%

Agg 0.7%

↑ +0.1%

P 0.7%

K 0.2%

Polymarket 0.7%

Vol $44.1K 0.6–0.7¢

Kalshi 0.2%

Vol $0 0.1–0.2¢

Hunter Biden

Vol $58.0K Spread 0.5%

Agg 0.7%

↑ +0.1%

P 0.7%

K 0.2%

Polymarket 0.7%

Vol $58.0K 0.6–0.7¢

Kalshi 0.2%

Vol $0 0.1–0.2¢

Kim Kardashian

Vol $23.2K Spread —

Agg 0.7%

— +0.0%

P 0.7%

Polymarket 0.7%

Vol $23.2K 0.6–0.7¢

Oprah Winfrey

Vol $139.8K Spread —

Agg 0.7%

↑ +0.2%

P 0.7%

Polymarket 0.7%

Vol $139.8K 0.6–0.7¢

Phil Murphy

Vol $18.5K Spread 0.6%

Agg 0.7%

↑ +0.1%

P 0.7%

K 0.1%

Polymarket 0.7%

Vol $18.5K 0.6–0.7¢

Kalshi 0.1%

Vol $0 0–0.1¢

Tim Walz

Vol $17.2K Spread 0.5%

Agg 0.7%

↑ +0.1%

P 0.7%

K 0.2%

Polymarket 0.7%

Vol $17.2K 0.6–0.7¢

Kalshi 0.2%

Vol $0 0.1–0.2¢

Gina Raimondo

Vol $27.0K Spread 0.4%

Agg 0.6%

↑ +0.2%

P 0.7%

K 0.3%

Polymarket 0.7%

Vol $26.9K 0.6–0.7¢

Kalshi 0.3%

Vol $51 0.2–0.3¢

Bernie Sanders

Vol $72.5K Spread 0.4%

Agg 0.5%

↑ +0.1%

P 0.5%

K 0.2%

Polymarket 0.5%

Vol $72.5K 0.5–0.6¢

Kalshi 0.2%

Vol $0 0.1–0.2¢

Jasmine Crockett

Vol $19.3K Spread —

Agg 0.5%

— +0.0%

P 0.5%

Polymarket 0.5%

Vol $19.3K 0.5–0.6¢

Jamie Dimon

Vol $0 Spread —

Agg 0.5%

— +0.0%

K 0.5%

Kalshi 0.5%

Vol $0 0.4–0.6¢

Zohran Mamdani

Vol $98.2K Spread 0.5%

Agg 0.3%

↓ -0.2%

NYC Mayor

P 0.8%

K 0.2%

Polymarket 0.8%

Vol $26.3K 0.7–0.8¢

Kalshi 0.2%

Vol $71.9K 0.1–0.3¢

Outcome	Aggregated	Spread	Volume	Kalshi	Polymarket	ForecastEx
GN Gavin Newsom California Governor	26.3% ↓ -8.5%	50.5%	$55.5K	Kalshi 25.5% 25–26¢ Vol $15.6K	Polymarket 26.7% 26.6–26.7¢ Vol $39.9K	ForecastEx 76.0% 76¢ Vol $0
AOC Alexandria Ocasio-Cortez NY Representative	8.8% ↓ -3.6%	1.5%	$5.8K	Kalshi 9.5% 9.4–9.5¢ Vol $1.7K	Polymarket 8.6% 8.5–8.6¢ Vol $4.1K	ForecastEx 10.0% 10¢ Vol $0
KH Kamala Harris	7.8% ↑ +3.9%	3.5%	$7.3K	Kalshi 7.9% 7.8–7.9¢ Vol $5.2K	Polymarket 7.6% 7.5–7.6¢ Vol $2.1K	ForecastEx 11.0% 11¢ Vol $0
JO Jon Ossoff	6.7% ↑ +3.1%	2.4%	$12.2K	Kalshi 9.0% 8.9–9¢ Vol $896	Polymarket 6.6% 6.5–6.6¢ Vol $11.3K	ForecastEx — —
PB Pete Buttigieg	4.4% ↓ -0.3%	3.8%	$8.3K	Kalshi 5.6% 5.5–5.6¢ Vol $641	Polymarket 4.3% 4.2–4.3¢ Vol $7.7K	ForecastEx 8.0% 8¢ Vol $0
JS Josh Shapiro	4.1% ↓ -1.3%	4.9%	$4.6K	Kalshi 5.4% 5.3–5.4¢ Vol $302	Polymarket 4.1% 4–4.1¢ Vol $4.3K	ForecastEx 9.0% 9¢ Vol $0
MK Mark Kelly	2.9% ↑ +1.0%	1.2%	$7.5K	Kalshi 3.9% 3.8–3.9¢ Vol $1.4K	Polymarket 2.7% 2.6–2.7¢ Vol $6.0K	ForecastEx — —
AB Andy Beshear	2.8% ↓ -2.0%	6.5%	$7.6K	Kalshi 4.0% 3.9–4¢ Vol $1.4K	Polymarket 2.6% 2.5–2.6¢ Vol $6.2K	ForecastEx 9.0% 9¢ Vol $0
RE Rahm Emanuel	2.8% ↑ +0.8%	1.3%	$13.9K	Kalshi 3.7% 3.6–3.7¢ Vol $4.7K	Polymarket 2.4% 2.3–2.4¢ Vol $9.3K	ForecastEx — —
JT James Talarico	2.4% ↑ +1.9%	—	$48	Kalshi 2.4% 2.3–2.5¢ Vol $48	Polymarket — —	ForecastEx — —
JS Jon Stewart Comedian	2.2% ↑ +1.4%	1.0%	$87.5K	Kalshi 1.2% 1.1–1.3¢ Vol $229	Polymarket 2.3% 2.2–2.3¢ Vol $87.3K	ForecastEx — —
JBP J.B. Pritzker	2.0% ↓ -0.2%	2.1%	$21.1K	Kalshi 2.9% 2.9–3¢ Vol $1.1K	Polymarket 2.0% 1.9–2¢ Vol $19.9K	ForecastEx 4.0% 4¢ Vol $0
RK Ro Khanna	2.0% ↑ +0.7%	1.1%	$26.6K	Kalshi 3.1% 3–3.1¢ Vol $309	Polymarket 2.0% 1.9–2¢ Vol $26.2K	ForecastEx — —
GW Gretchen Whitmer	1.4% ↓ -3.2%	2.7%	$27.1K	Kalshi 1.4% 1.3–1.4¢ Vol $43	Polymarket 1.4% 1.3–1.4¢ Vol $27.1K	ForecastEx 4.0% 4¢ Vol $0
WM Wes Moore	1.3% ↓ -1.2%	3.8%	$20.2K	Kalshi 2.0% 1.9–2.1¢ Vol $801	Polymarket 1.3% 1.2–1.3¢ Vol $19.4K	ForecastEx 5.0% 5¢ Vol $0
RC Roy Cooper	1.2% ↑ +0.5%	0.7%	$10.7K	Kalshi 0.4% 0.4–0.5¢ Vol $0	Polymarket 1.2% 1.1–1.2¢ Vol $10.7K	ForecastEx — —
MO Michelle Obama	1.1% ↑ +0.1%	0.2%	$30.5K	Kalshi 1.3% 1.2–1.4¢ Vol $9	Polymarket 1.1% 1–1.1¢ Vol $30.5K	ForecastEx — —
JF John Fetterman	1.0% ↓ -0.2%	0.9%	$19.5K	Kalshi 0.2% 0.1–0.2¢ Vol $3	Polymarket 1.1% 1–1.1¢ Vol $19.5K	ForecastEx — —
SAS Stephen A. Smith	1.0% ↑ +0.1%	0.5%	$14.7K	Kalshi 0.5% 0.5–0.6¢ Vol $50	Polymarket 1.1% 1–1.1¢ Vol $14.7K	ForecastEx — —
DJ Dwayne Johnson	1.0% ↓ -0.2%	0.8%	$44.3K	Kalshi 0.3% 0.2–0.3¢ Vol $195	Polymarket 1.1% 1–1.1¢ Vol $44.1K	ForecastEx — —
CC Chelsea Clinton	1.0% ↑ +0.4%	—	$148.2K	Kalshi — —	Polymarket 1.0% 0.9–1¢ Vol $148.2K	ForecastEx — —
MC Mark Cuban	1.0% ↑ +0.2%	0.2%	$12.0K	Kalshi 0.8% 0.7–0.8¢ Vol $0	Polymarket 1.0% 0.9–1¢ Vol $12.0K	ForecastEx — —
CB Cory Booker	0.9% ↑ +0.2%	0.2%	$14.2K	Kalshi 0.8% 0.7–0.8¢ Vol $25	Polymarket 1.0% 0.9–1¢ Vol $14.2K	ForecastEx — —
ES Elissa Slotkin	0.8% ↑ +0.3%	—	$3	Kalshi 0.8% 0.7–0.9¢ Vol $3	Polymarket — —	ForecastEx — —
BO Barack Obama	0.8% ↑ +0.1%	0.5%	$26.8K	Kalshi 0.3% 0.2–0.3¢ Vol $0	Polymarket 0.8% 0.7–0.8¢ Vol $26.8K	ForecastEx — —
JP Jared Polis	0.8% ↓ -0.2%	0.3%	$21.9K	Kalshi 0.4% 0.4–0.5¢ Vol $0	Polymarket 0.8% 0.7–0.8¢ Vol $21.9K	ForecastEx — —
MR MrBeast	0.8% ↑ +0.2%	—	$33.8K	Kalshi — —	Polymarket 0.8% 0.7–0.8¢ Vol $33.8K	ForecastEx — —
RW Raphael Warnock	0.8% ↑ +0.2%	0.3%	$15.2K	Kalshi 0.4% 0.4–0.5¢ Vol $1	Polymarket 0.8% 0.7–0.8¢ Vol $15.2K	ForecastEx — —
RG Ruben Gallego	0.8% ↓ -0.3%	0.0%	$71.0K	Kalshi 0.8% 0.7–0.8¢ Vol $0	Polymarket 0.8% 0.7–0.8¢ Vol $71.0K	ForecastEx — —
LJ Lebron James	0.7% ↓ -0.1%	0.7%	$25.2K	Kalshi 0.1% 0–0.1¢ Vol $4	Polymarket 0.8% 0.7–0.8¢ Vol $25.2K	ForecastEx — —
LC Liz Cheney	0.7% ↑ +0.2%	0.7%	$27.7K	Kalshi 0.1% 0–0.1¢ Vol $5	Polymarket 0.8% 0.7–0.8¢ Vol $27.7K	ForecastEx — —
AY Andrew Yang	0.7% ↑ +0.1%	—	$17.2K	Kalshi — —	Polymarket 0.7% 0.6–0.7¢ Vol $17.2K	ForecastEx — —
BOR Beto O’Rourke	0.7% ↓ -0.2%	—	$39.0K	Kalshi — —	Polymarket 0.7% 0.6–0.7¢ Vol $39.0K	ForecastEx — —
CM Chris Murphy	0.7% — +0.0%	0.1%	$154.3K	Kalshi 0.5% 0.5–0.6¢ Vol $0	Polymarket 0.7% 0.6–0.7¢ Vol $154.3K	ForecastEx — —
GC George Clooney	0.7% ↑ +0.1%	—	$19.4K	Kalshi — —	Polymarket 0.7% 0.6–0.7¢ Vol $19.4K	ForecastEx — —
HC Hilary Clinton	0.7% ↑ +0.1%	0.5%	$44.1K	Kalshi 0.2% 0.1–0.2¢ Vol $0	Polymarket 0.7% 0.6–0.7¢ Vol $44.1K	ForecastEx — —
HB Hunter Biden	0.7% ↑ +0.1%	0.5%	$58.0K	Kalshi 0.2% 0.1–0.2¢ Vol $0	Polymarket 0.7% 0.6–0.7¢ Vol $58.0K	ForecastEx — —
KK Kim Kardashian	0.7% — +0.0%	—	$23.2K	Kalshi — —	Polymarket 0.7% 0.6–0.7¢ Vol $23.2K	ForecastEx — —
OW Oprah Winfrey	0.7% ↑ +0.2%	—	$139.8K	Kalshi — —	Polymarket 0.7% 0.6–0.7¢ Vol $139.8K	ForecastEx — —
PM Phil Murphy	0.7% ↑ +0.1%	0.6%	$18.5K	Kalshi 0.1% 0–0.1¢ Vol $0	Polymarket 0.7% 0.6–0.7¢ Vol $18.5K	ForecastEx — —
TW Tim Walz	0.7% ↑ +0.1%	0.5%	$17.2K	Kalshi 0.2% 0.1–0.2¢ Vol $0	Polymarket 0.7% 0.6–0.7¢ Vol $17.2K	ForecastEx — —
GR Gina Raimondo	0.6% ↑ +0.2%	0.4%	$27.0K	Kalshi 0.3% 0.2–0.3¢ Vol $51	Polymarket 0.7% 0.6–0.7¢ Vol $26.9K	ForecastEx — —
BS Bernie Sanders	0.5% ↑ +0.1%	0.4%	$72.5K	Kalshi 0.2% 0.1–0.2¢ Vol $0	Polymarket 0.5% 0.5–0.6¢ Vol $72.5K	ForecastEx — —
JC Jasmine Crockett	0.5% — +0.0%	—	$19.3K	Kalshi — —	Polymarket 0.5% 0.5–0.6¢ Vol $19.3K	ForecastEx — —
JD Jamie Dimon	0.5% — +0.0%	—	$0	Kalshi 0.5% 0.4–0.6¢ Vol $0	Polymarket — —	ForecastEx — —
ZM Zohran Mamdani NYC Mayor	0.3% ↓ -0.2%	0.5%	$98.2K	Kalshi 0.2% 0.1–0.3¢ Vol $71.9K	Polymarket 0.8% 0.7–0.8¢ Vol $26.3K	ForecastEx — —

Arbitrage Scanner

Current cross-venue opportunities with fee calculations

Minimum Spread 1.5%

Include fees

Show only actionable

Pairs (Venue-to-Venue)

Outcome	Venue Pair	Leg A (Buy)	Leg B (Sell)	Gross Spread	After Fees	Actionable
JO Jon Ossoff	Polymarket → Kalshi	Buy @ P 6.6¢	Sell @ K 8.9¢	+2.30%	+2.21%	Yes
AB Andy Beshear	Polymarket → Kalshi	Buy @ P 2.6¢	Sell @ K 3.9¢	+1.30%	+1.23%	No
PB Pete Buttigieg	Polymarket → Kalshi	Buy @ P 4.3¢	Sell @ K 5.5¢	+1.20%	+1.13%	No
JS Josh Shapiro	Polymarket → Kalshi	Buy @ P 4.1¢	Sell @ K 5.3¢	+1.20%	+1.13%	No
RE Rahm Emanuel	Polymarket → Kalshi	Buy @ P 2.4¢	Sell @ K 3.6¢	+1.20%	+1.13%	No
MK Mark Kelly	Polymarket → Kalshi	Buy @ P 2.7¢	Sell @ K 3.8¢	+1.10%	+1.03%	No
RK Ro Khanna	Polymarket → Kalshi	Buy @ P 2¢	Sell @ K 3¢	+1.00%	+0.93%	No
JBP J.B. Pritzker	Polymarket → Kalshi	Buy @ P 2¢	Sell @ K 2.9¢	+0.90%	+0.83%	No
JS Jon Stewart Comedian	Kalshi → Polymarket	Buy @ K 1.3¢	Sell @ P 2.2¢	+0.90%	+0.83%	No
JF John Fetterman	Kalshi → Polymarket	Buy @ K 0.2¢	Sell @ P 1¢	+0.80%	+0.73%	No
AOC Alexandria Ocasio-Cortez NY Representative	Polymarket → Kalshi	Buy @ P 8.6¢	Sell @ K 9.4¢	+0.80%	+0.71%	No
DJ Dwayne Johnson	Kalshi → Polymarket	Buy @ K 0.3¢	Sell @ P 1¢	+0.70%	+0.63%	No
WM Wes Moore	Polymarket → Kalshi	Buy @ P 1.3¢	Sell @ K 1.9¢	+0.60%	+0.53%	No
LJ Lebron James	Kalshi → Polymarket	Buy @ K 0.1¢	Sell @ P 0.7¢	+0.60%	+0.53%	No
LC Liz Cheney	Kalshi → Polymarket	Buy @ K 0.1¢	Sell @ P 0.7¢	+0.60%	+0.53%	No
RC Roy Cooper	Kalshi → Polymarket	Buy @ K 0.5¢	Sell @ P 1.1¢	+0.60%	+0.53%	No
PM Phil Murphy	Kalshi → Polymarket	Buy @ K 0.1¢	Sell @ P 0.6¢	+0.50%	+0.43%	No
GN Gavin Newsom California Governor	Kalshi → Polymarket	Buy @ K 26¢	Sell @ P 26.6¢	+0.60%	+0.34%	No
SAS Stephen A. Smith	Kalshi → Polymarket	Buy @ K 0.6¢	Sell @ P 1¢	+0.40%	+0.33%	No
BO Barack Obama	Kalshi → Polymarket	Buy @ K 0.3¢	Sell @ P 0.7¢	+0.40%	+0.33%	No
HC Hilary Clinton	Kalshi → Polymarket	Buy @ K 0.2¢	Sell @ P 0.6¢	+0.40%	+0.33%	No
HB Hunter Biden	Kalshi → Polymarket	Buy @ K 0.2¢	Sell @ P 0.6¢	+0.40%	+0.33%	No
TW Tim Walz	Kalshi → Polymarket	Buy @ K 0.2¢	Sell @ P 0.6¢	+0.40%	+0.33%	No
ZM Zohran Mamdani NYC Mayor	Kalshi → Polymarket	Buy @ K 0.3¢	Sell @ P 0.7¢	+0.40%	+0.33%	No
GR Gina Raimondo	Kalshi → Polymarket	Buy @ K 0.3¢	Sell @ P 0.6¢	+0.30%	+0.23%	No
BS Bernie Sanders	Kalshi → Polymarket	Buy @ K 0.2¢	Sell @ P 0.5¢	+0.30%	+0.23%	No
JP Jared Polis	Kalshi → Polymarket	Buy @ K 0.5¢	Sell @ P 0.7¢	+0.20%	+0.13%	No
RW Raphael Warnock	Kalshi → Polymarket	Buy @ K 0.5¢	Sell @ P 0.7¢	+0.20%	+0.13%	No
KH Kamala Harris	Polymarket → Kalshi	Buy @ P 7.6¢	Sell @ K 7.8¢	+0.20%	+0.12%	No
MO Michelle Obama	Polymarket → Kalshi	Buy @ P 1.1¢	Sell @ K 1.2¢	+0.10%	+0.03%	No
MC Mark Cuban	Kalshi → Polymarket	Buy @ K 0.8¢	Sell @ P 0.9¢	+0.10%	+0.03%	No
CB Cory Booker	Kalshi → Polymarket	Buy @ K 0.8¢	Sell @ P 0.9¢	+0.10%	+0.03%	No
CM Chris Murphy	Kalshi → Polymarket	Buy @ K 0.6¢	Sell @ P 0.6¢	+0.00%	-0.07%	No
RG Ruben Gallego	Kalshi → Polymarket	Buy @ K 0.8¢	Sell @ P 0.7¢	-0.10%	-0.17%	No
GW Gretchen Whitmer	Kalshi → Polymarket	Buy @ K 1.4¢	Sell @ P 1.3¢	-0.10%	-0.17%	No

Outcome Diff

Outcome A	Outcome B	Venue	A Odds	B Odds	Diff	Strategy
GN Gavin Newsom	JS Jon Stewart	Polymarket	A 26.7%	B 2.3%	+24.40%	Buy spread
GN Gavin Newsom	RE Rahm Emanuel	Polymarket	A 26.7%	B 2.4%	+24.30%	Buy spread
GN Gavin Newsom	AB Andy Beshear	Polymarket	A 26.7%	B 2.6%	+24.10%	Buy spread
GN Gavin Newsom	MK Mark Kelly	Polymarket	A 26.7%	B 2.7%	+24.00%	Buy spread
GN Gavin Newsom	JS Josh Shapiro	Polymarket	A 26.7%	B 4.1%	+22.60%	Buy spread
GN Gavin Newsom	RK Ro Khanna	Kalshi	A 25.5%	B 3.1%	+22.45%	Buy spread
GN Gavin Newsom	PB Pete Buttigieg	Polymarket	A 26.7%	B 4.3%	+22.40%	Buy spread
GN Gavin Newsom	RE Rahm Emanuel	Kalshi	A 25.5%	B 3.7%	+21.85%	Buy spread
GN Gavin Newsom	MK Mark Kelly	Kalshi	A 25.5%	B 3.9%	+21.65%	Buy spread
GN Gavin Newsom	AB Andy Beshear	Kalshi	A 25.5%	B 4.0%	+21.55%	Buy spread
GN Gavin Newsom	JS Josh Shapiro	Kalshi	A 25.5%	B 5.4%	+20.15%	Buy spread
GN Gavin Newsom	JO Jon Ossoff	Polymarket	A 26.7%	B 6.6%	+20.10%	Buy spread
GN Gavin Newsom	PB Pete Buttigieg	Kalshi	A 25.5%	B 5.6%	+19.95%	Buy spread
GN Gavin Newsom	KH Kamala Harris	Polymarket	A 26.7%	B 7.6%	+19.10%	Buy spread
GN Gavin Newsom	AOC Alexandria Ocasio-Cortez	Polymarket	A 26.7%	B 8.6%	+18.10%	Buy spread
GN Gavin Newsom	KH Kamala Harris	Kalshi	A 25.5%	B 7.9%	+17.65%	Buy spread
GN Gavin Newsom	JO Jon Ossoff	Kalshi	A 25.5%	B 9.0%	+16.55%	Buy spread
GN Gavin Newsom	AOC Alexandria Ocasio-Cortez	Kalshi	A 25.5%	B 9.5%	+16.05%	Buy spread
AOC Alexandria Ocasio-Cortez	RK Ro Khanna	Kalshi	A 9.5%	B 3.1%	+6.40%	Buy spread
AOC Alexandria Ocasio-Cortez	JS Jon Stewart	Polymarket	A 8.6%	B 2.3%	+6.30%	Buy spread
AOC Alexandria Ocasio-Cortez	RE Rahm Emanuel	Polymarket	A 8.6%	B 2.4%	+6.20%	Buy spread
AOC Alexandria Ocasio-Cortez	AB Andy Beshear	Polymarket	A 8.6%	B 2.6%	+6.00%	Buy spread
AOC Alexandria Ocasio-Cortez	MK Mark Kelly	Polymarket	A 8.6%	B 2.7%	+5.90%	Buy spread
JO Jon Ossoff	RK Ro Khanna	Kalshi	A 9.0%	B 3.1%	+5.90%	Buy spread
AOC Alexandria Ocasio-Cortez	RE Rahm Emanuel	Kalshi	A 9.5%	B 3.7%	+5.80%	Buy spread
AOC Alexandria Ocasio-Cortez	MK Mark Kelly	Kalshi	A 9.5%	B 3.9%	+5.60%	Buy spread
AOC Alexandria Ocasio-Cortez	AB Andy Beshear	Kalshi	A 9.5%	B 4.0%	+5.50%	Buy spread
JO Jon Ossoff	RE Rahm Emanuel	Kalshi	A 9.0%	B 3.7%	+5.30%	Buy spread
KH Kamala Harris	JS Jon Stewart	Polymarket	A 7.6%	B 2.3%	+5.30%	Buy spread
KH Kamala Harris	RE Rahm Emanuel	Polymarket	A 7.6%	B 2.4%	+5.20%	Buy spread

Kalshi Trading Fee 1% (min $0.07, max $1.75) per side

Polymarket Trading Fee 0% (gas only)

Gemini Trading Fee 0.40% per side

Polymarket US Trading Fee 0% (gas only)

After-fee spreads apply the configured taker-fee model per side. Depth/slippage is not modeled in this scanner.

Methodology & Data Mapping

How we aggregate, normalize, and map cross-platform data

Aggregation Method

Default: Volume-Weighted Average Price (VWAP)

Weights each mapped market by its reported 24H USD volume at snapshot time. If volume is unavailable, we fall back to a simple average for that snapshot.

Use the VWAP/Simple toggle above the chart to switch aggregation views.

Data Sources & Cadence

Kalshi: Official API (best bid/ask + last + 24H volume/liquidity when available).

Polymarket: Market data via their API (token prices + best bid/ask + 24H volume/liquidity when available).

ForecastEx: FEX API (price from latest_prices; 24H USD volume estimated from trades as sum(quantity * yes_price); no bid/ask).

Event data is updated hourly. Older history is downsampled.

Outcome Mapping

Each event links one or more markets per provider. We normalize labels, map provider outcomes into a shared outcome list, and merge mapped markets where appropriate.

Spread & Liquidity

Cross-venue spread: Max–min difference across available venue probabilities for the same outcome.

Liquidity: Relative per-venue indicators based on provider liquidity fields (no depth/slippage modeling).

Arbitrage: Computed from best bid/ask when available (otherwise mid); after-fee spread applies the configured fee model only.

Prediction Markets 2028 Democratic Presidential Nominee

2028 Democratic Presidential Nominee Odds

Probability Over Time

Current Odds Snapshot

Arbitrage Scanner

Pairs (Venue-to-Venue)

Outcome Diff

Methodology & Data Mapping