Prediction Markets 2028 Democratic Presidential Nominee

2028 Democratic Presidential Nominee Odds

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Updated 24 minutes ago · 9:24 AM PDT

Gavin Newsom leads the 2028 Democratic nomination at 22.5%, 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 9.0% chance, still weighing a presidential run against a 2028 Senate primary challenge to Chuck Schumer. Jon Ossoff rounds out the top three at 7.9% 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

3.53%

Rahm Emanuel → View arbs

Current Favorite

22.5%

Gavin Newsom 12.3%

24H Volume (Share)

$1.5M

Momentum Leader

+4.3%

Jon Ossoff YTD change

Current Odds Snapshot

Current probabilities across platforms with liquidity indicators

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Gavin Newsom

Vol $14.6K Spread 8.5%

Agg 22.5%

↓ -12.3%

California Governor

F 30.0%

P 23.2%

K 21.5%

AOC

Alexandria Ocasio-Cortez

Vol $13.7K Spread 2.2%

Agg 9.0%

↓ -3.4%

NY Representative

F 11.0%

K 9.8%

P 8.9%

Jon Ossoff

Vol $3.2K Spread 1.0%

Agg 7.9%

↑ +4.3%

K 8.8%

P 7.8%

Kamala Harris

Vol $9.8K Spread 7.4%

Agg 7.6%

↑ +3.8%

F 15.0%

K 7.6%

P 7.6%

Josh Shapiro

Vol $6.9K Spread 5.1%

Agg 5.2%

↓ -0.2%

F 10.0%

P 5.3%

K 5.0%

Rahm Emanuel

Vol $9.4K Spread 3.7%

Agg 4.8%

↑ +2.8%

K 5.6%

P 1.8%

Pete Buttigieg

Vol $6.0K Spread 6.7%

Agg 4.5%

↓ -0.1%

F 11.0%

K 5.5%

P 4.4%

Andy Beshear

Vol $35.0K Spread 6.3%

Agg 3.4%

↓ -1.4%

F 9.0%

K 3.5%

P 2.8%

Mark Kelly

Vol $3.6K Spread 1.7%

Agg 3.1%

↑ +1.2%

K 3.4%

P 1.8%

JBP

J.B. Pritzker

Vol $2.7K Spread 2.4%

Agg 2.6%

↑ +0.4%

F 4.0%

K 4.0%

P 1.7%

Jon Stewart

Vol $11.6K Spread 0.5%

Agg 2.1%

↑ +1.2%

Comedian

K 2.1%

P 1.7%

Ro Khanna

Vol $17.0K Spread 0.6%

Agg 1.9%

↑ +0.6%

K 2.5%

P 1.8%

Wes Moore

Vol $5.2K Spread 3.7%

Agg 1.7%

↓ -0.7%

F 5.0%

K 2.2%

P 1.4%

Michelle Obama

Vol $11.5K Spread 0.3%

Agg 1.4%

↑ +0.4%

K 1.7%

P 1.4%

Elissa Slotkin

Vol $1.4K Spread —

Agg 1.4%

↑ +0.9%

K 1.4%

Kalshi 1.4%

Vol $1.4K 1.3–1.4¢

James Talarico

Vol $170 Spread —

Agg 1.3%

↑ +0.8%

K 1.3%

Kalshi 1.3%

Vol $170 1.2–1.4¢

Dwayne Johnson

Vol $11.3K Spread 1.0%

Agg 1.2%

— +0.0%

P 1.3%

K 0.3%

Hunter Biden

Vol $551.2K Spread 0.3%

Agg 1.0%

↑ +0.4%

K 1.2%

P 0.9%

Chelsea Clinton

Vol $2.6K Spread —

Agg 1.0%

↑ +0.4%

P 1.0%

Polymarket 1.0%

Vol $2.6K 0.9–1¢

Mark Cuban

Vol $5.2K Spread 0.0%

Agg 1.0%

↑ +0.2%

K 1.0%

P 1.0%

Roy Cooper

Vol $1.5K Spread 0.7%

Agg 0.9%

↑ +0.3%

P 1.0%

K 0.3%

Cory Booker

Vol $2.1K Spread 0.3%

Agg 0.9%

↑ +0.2%

P 1.0%

K 0.7%

SAS

Stephen A. Smith

Vol $7.4K Spread 0.2%

Agg 0.9%

— +0.0%

P 1.1%

K 0.9%

Gretchen Whitmer

Vol $10.2K Spread 7.2%

Agg 0.9%

↓ -3.7%

F 8.0%

K 1.1%

P 0.9%

Chris Murphy

Vol $124.2K Spread 0.2%

Agg 0.9%

↑ +0.2%

P 0.9%

K 0.7%

John Fetterman

Vol $6.0K Spread 0.6%

Agg 0.8%

↓ -0.4%

P 0.9%

K 0.3%

Barack Obama

Vol $29.7K Spread 0.6%

Agg 0.8%

↑ +0.1%

P 0.8%

K 0.2%

Bernie Sanders

Vol $25.6K Spread 0.4%

Agg 0.8%

↑ +0.3%

P 0.8%

K 0.4%

Gina Raimondo

Vol $32.2K Spread 0.5%

Agg 0.8%

↑ +0.3%

P 0.8%

K 0.2%

Lebron James

Vol $31.4K Spread 0.6%

Agg 0.8%

↓ -0.1%

P 0.8%

K 0.2%

Liz Cheney

Vol $29.3K Spread 0.7%

Agg 0.8%

↑ +0.2%

P 0.8%

K 0.1%

MrBeast

Vol $27.0K Spread —

Agg 0.8%

↑ +0.2%

P 0.8%

Polymarket 0.8%

Vol $27.0K 0.7–0.8¢

Oprah Winfrey

Vol $24.0K Spread —

Agg 0.8%

↑ +0.3%

P 0.8%

Polymarket 0.8%

Vol $24.0K 0.7–0.8¢

Raphael Warnock

Vol $13.9K Spread 0.3%

Agg 0.8%

↑ +0.2%

P 0.8%

K 0.4%

Ruben Gallego

Vol $26.2K Spread 0.0%

Agg 0.8%

↓ -0.3%

K 0.8%

P 0.8%

Zohran Mamdani

Vol $28.2K Spread 0.5%

Agg 0.7%

↑ +0.2%

NYC Mayor

P 0.8%

K 0.3%

Hilary Clinton

Vol $31.2K Spread 0.6%

Agg 0.7%

↑ +0.2%

P 0.8%

K 0.2%

Jared Polis

Vol $29.8K Spread 0.4%

Agg 0.7%

↓ -0.2%

P 0.8%

K 0.4%

Andrew Yang

Vol $32.9K Spread —

Agg 0.7%

↑ +0.1%

P 0.7%

Polymarket 0.7%

Vol $32.9K 0.6–0.7¢

BOR

Beto O’Rourke

Vol $33.1K Spread —

Agg 0.7%

↓ -0.2%

P 0.7%

Polymarket 0.7%

Vol $33.1K 0.6–0.7¢

George Clooney

Vol $34.6K Spread —

Agg 0.7%

↑ +0.1%

P 0.7%

Polymarket 0.7%

Vol $34.6K 0.6–0.7¢

Jasmine Crockett

Vol $34.6K Spread —

Agg 0.7%

↑ +0.1%

P 0.7%

Polymarket 0.7%

Vol $34.6K 0.6–0.7¢

Kim Kardashian

Vol $33.1K Spread —

Agg 0.7%

— +0.0%

P 0.7%

Polymarket 0.7%

Vol $33.1K 0.6–0.7¢

Phil Murphy

Vol $42.4K Spread 0.6%

Agg 0.7%

↑ +0.1%

P 0.7%

K 0.1%

Tim Walz

Vol $40.2K Spread 0.6%

Agg 0.7%

↑ +0.1%

P 0.7%

K 0.1%

Jamie Dimon

Vol $6 Spread —

Agg 0.3%

↓ -0.3%

K 0.3%

Kalshi 0.3%

Vol $6 0.2–0.3¢

Outcome	Aggregated	Spread	Volume	Kalshi	Polymarket	ForecastEx
GN Gavin Newsom California Governor	22.5% ↓ -12.3%	8.5%	$14.6K	Kalshi 21.5% 21–22¢ Vol $5.7K	Polymarket 23.2% 23.1–23.3¢ Vol $8.9K	ForecastEx 30.0% 30¢ Vol $0
AOC Alexandria Ocasio-Cortez NY Representative	9.0% ↓ -3.4%	2.2%	$13.7K	Kalshi 9.8% 9.7–9.8¢ Vol $2.0K	Polymarket 8.9% 8.8–8.9¢ Vol $11.6K	ForecastEx 11.0% 11¢ Vol $0
JO Jon Ossoff	7.9% ↑ +4.3%	1.0%	$3.2K	Kalshi 8.8% 8.7–8.9¢ Vol $500	Polymarket 7.8% 7.7–7.8¢ Vol $2.7K	ForecastEx — —
KH Kamala Harris	7.6% ↑ +3.8%	7.4%	$9.8K	Kalshi 7.6% 7.6–7.7¢ Vol $3.4K	Polymarket 7.6% 7.6–7.7¢ Vol $6.4K	ForecastEx 15.0% 15¢ Vol $0
JS Josh Shapiro	5.2% ↓ -0.2%	5.1%	$6.9K	Kalshi 5.0% 4.9–5¢ Vol $2.1K	Polymarket 5.3% 5.2–5.3¢ Vol $4.8K	ForecastEx 10.0% 10¢ Vol $0
RE Rahm Emanuel	4.8% ↑ +2.8%	3.7%	$9.4K	Kalshi 5.6% 5.5–5.6¢ Vol $7.4K	Polymarket 1.8% 1.8–1.9¢ Vol $1.9K	ForecastEx — —
PB Pete Buttigieg	4.5% ↓ -0.1%	6.7%	$6.0K	Kalshi 5.5% 5.4–5.6¢ Vol $972	Polymarket 4.4% 4.3–4.4¢ Vol $5.0K	ForecastEx 11.0% 11¢ Vol $0
AB Andy Beshear	3.4% ↓ -1.4%	6.3%	$35.0K	Kalshi 3.5% 3.4–3.6¢ Vol $31.1K	Polymarket 2.8% 2.7–2.8¢ Vol $3.9K	ForecastEx 9.0% 9¢ Vol $0
MK Mark Kelly	3.1% ↑ +1.2%	1.7%	$3.6K	Kalshi 3.4% 3.3–3.5¢ Vol $3.0K	Polymarket 1.8% 1.7–1.8¢ Vol $569	ForecastEx — —
JBP J.B. Pritzker	2.6% ↑ +0.4%	2.4%	$2.7K	Kalshi 4.0% 3.9–4¢ Vol $1.1K	Polymarket 1.7% 1.6–1.7¢ Vol $1.6K	ForecastEx 4.0% 4¢ Vol $0
JS Jon Stewart Comedian	2.1% ↑ +1.2%	0.5%	$11.6K	Kalshi 2.1% 1.9–2.3¢ Vol $10.6K	Polymarket 1.7% 1.6–1.7¢ Vol $1.0K	ForecastEx — —
RK Ro Khanna	1.9% ↑ +0.6%	0.6%	$17.0K	Kalshi 2.5% 2.4–2.5¢ Vol $1.4K	Polymarket 1.8% 1.8–1.9¢ Vol $15.6K	ForecastEx — —
WM Wes Moore	1.7% ↓ -0.7%	3.7%	$5.2K	Kalshi 2.2% 2.1–2.2¢ Vol $2.3K	Polymarket 1.4% 1.3–1.4¢ Vol $2.9K	ForecastEx 5.0% 5¢ Vol $0
MO Michelle Obama	1.4% ↑ +0.4%	0.3%	$11.5K	Kalshi 1.7% 1.6–1.7¢ Vol $157	Polymarket 1.4% 1.3–1.4¢ Vol $11.4K	ForecastEx — —
ES Elissa Slotkin	1.4% ↑ +0.9%	—	$1.4K	Kalshi 1.4% 1.3–1.4¢ Vol $1.4K	Polymarket — —	ForecastEx — —
JT James Talarico	1.3% ↑ +0.8%	—	$170	Kalshi 1.3% 1.2–1.4¢ Vol $170	Polymarket — —	ForecastEx — —
DJ Dwayne Johnson	1.2% — +0.0%	1.0%	$11.3K	Kalshi 0.3% 0.2–0.4¢ Vol $84	Polymarket 1.3% 1.2–1.3¢ Vol $11.3K	ForecastEx — —
HB Hunter Biden	1.0% ↑ +0.4%	0.3%	$551.2K	Kalshi 1.2% 1.1–1.2¢ Vol $211.1K	Polymarket 0.9% 0.8–0.9¢ Vol $340.1K	ForecastEx — —
CC Chelsea Clinton	1.0% ↑ +0.4%	—	$2.6K	Kalshi — —	Polymarket 1.0% 0.9–1¢ Vol $2.6K	ForecastEx — —
MC Mark Cuban	1.0% ↑ +0.2%	0.0%	$5.2K	Kalshi 1.0% 0.9–1¢ Vol $94	Polymarket 1.0% 0.9–1¢ Vol $5.1K	ForecastEx — —
RC Roy Cooper	0.9% ↑ +0.3%	0.7%	$1.5K	Kalshi 0.3% 0.2–0.3¢ Vol $5	Polymarket 1.0% 0.9–1¢ Vol $1.5K	ForecastEx — —
CB Cory Booker	0.9% ↑ +0.2%	0.3%	$2.1K	Kalshi 0.7% 0.6–0.7¢ Vol $162	Polymarket 1.0% 0.9–1¢ Vol $1.9K	ForecastEx — —
SAS Stephen A. Smith	0.9% — +0.0%	0.2%	$7.4K	Kalshi 0.9% 0.8–0.9¢ Vol $5.0K	Polymarket 1.1% 1–1.1¢ Vol $2.4K	ForecastEx — —
GW Gretchen Whitmer	0.9% ↓ -3.7%	7.2%	$10.2K	Kalshi 1.1% 1–1.1¢ Vol $432	Polymarket 0.9% 0.8–0.9¢ Vol $9.8K	ForecastEx 8.0% 8¢ Vol $0
CM Chris Murphy	0.9% ↑ +0.2%	0.2%	$124.2K	Kalshi 0.7% 0.6–0.7¢ Vol $0	Polymarket 0.9% 0.8–0.9¢ Vol $124.2K	ForecastEx — —
JF John Fetterman	0.8% ↓ -0.4%	0.6%	$6.0K	Kalshi 0.3% 0.2–0.3¢ Vol $7	Polymarket 0.9% 0.8–0.9¢ Vol $6.0K	ForecastEx — —
BO Barack Obama	0.8% ↑ +0.1%	0.6%	$29.7K	Kalshi 0.2% 0.1–0.2¢ Vol $0	Polymarket 0.8% 0.7–0.8¢ Vol $29.7K	ForecastEx — —
BS Bernie Sanders	0.8% ↑ +0.3%	0.4%	$25.6K	Kalshi 0.4% 0.3–0.4¢ Vol $0	Polymarket 0.8% 0.7–0.8¢ Vol $25.6K	ForecastEx — —
GR Gina Raimondo	0.8% ↑ +0.3%	0.5%	$32.2K	Kalshi 0.2% 0.1–0.3¢ Vol $0	Polymarket 0.8% 0.7–0.8¢ Vol $32.2K	ForecastEx — —
LJ Lebron James	0.8% ↓ -0.1%	0.6%	$31.4K	Kalshi 0.2% 0.1–0.2¢ Vol $0	Polymarket 0.8% 0.7–0.8¢ Vol $31.4K	ForecastEx — —
LC Liz Cheney	0.8% ↑ +0.2%	0.7%	$29.3K	Kalshi 0.1% 0–0.1¢ Vol $0	Polymarket 0.8% 0.7–0.8¢ Vol $29.3K	ForecastEx — —
MR MrBeast	0.8% ↑ +0.2%	—	$27.0K	Kalshi — —	Polymarket 0.8% 0.7–0.8¢ Vol $27.0K	ForecastEx — —
OW Oprah Winfrey	0.8% ↑ +0.3%	—	$24.0K	Kalshi — —	Polymarket 0.8% 0.7–0.8¢ Vol $24.0K	ForecastEx — —
RW Raphael Warnock	0.8% ↑ +0.2%	0.3%	$13.9K	Kalshi 0.4% 0.4–0.5¢ Vol $0	Polymarket 0.8% 0.7–0.8¢ Vol $13.9K	ForecastEx — —
RG Ruben Gallego	0.8% ↓ -0.3%	0.0%	$26.2K	Kalshi 0.8% 0.7–0.8¢ Vol $680	Polymarket 0.8% 0.7–0.8¢ Vol $25.5K	ForecastEx — —
ZM Zohran Mamdani NYC Mayor	0.7% ↑ +0.2%	0.5%	$28.2K	Kalshi 0.3% 0.2–0.3¢ Vol $21	Polymarket 0.8% 0.7–0.8¢ Vol $28.2K	ForecastEx — —
HC Hilary Clinton	0.7% ↑ +0.2%	0.6%	$31.2K	Kalshi 0.2% 0.1–0.2¢ Vol $116	Polymarket 0.8% 0.7–0.8¢ Vol $31.1K	ForecastEx — —
JP Jared Polis	0.7% ↓ -0.2%	0.4%	$29.8K	Kalshi 0.4% 0.3–0.4¢ Vol $200	Polymarket 0.8% 0.7–0.8¢ Vol $29.6K	ForecastEx — —
AY Andrew Yang	0.7% ↑ +0.1%	—	$32.9K	Kalshi — —	Polymarket 0.7% 0.6–0.7¢ Vol $32.9K	ForecastEx — —
BOR Beto O’Rourke	0.7% ↓ -0.2%	—	$33.1K	Kalshi — —	Polymarket 0.7% 0.6–0.7¢ Vol $33.1K	ForecastEx — —
GC George Clooney	0.7% ↑ +0.1%	—	$34.6K	Kalshi — —	Polymarket 0.7% 0.6–0.7¢ Vol $34.6K	ForecastEx — —
JC Jasmine Crockett	0.7% ↑ +0.1%	—	$34.6K	Kalshi — —	Polymarket 0.7% 0.6–0.7¢ Vol $34.6K	ForecastEx — —
KK Kim Kardashian	0.7% — +0.0%	—	$33.1K	Kalshi — —	Polymarket 0.7% 0.6–0.7¢ Vol $33.1K	ForecastEx — —
PM Phil Murphy	0.7% ↑ +0.1%	0.6%	$42.4K	Kalshi 0.1% 0–0.1¢ Vol $0	Polymarket 0.7% 0.6–0.7¢ Vol $42.4K	ForecastEx — —
TW Tim Walz	0.7% ↑ +0.1%	0.6%	$40.2K	Kalshi 0.1% 0–0.1¢ Vol $0	Polymarket 0.7% 0.6–0.7¢ Vol $40.2K	ForecastEx — —
JD Jamie Dimon	0.3% ↓ -0.3%	—	$6	Kalshi 0.3% 0.2–0.3¢ Vol $6	Polymarket — —	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	Trade Now
RE Rahm Emanuel	Polymarket → Kalshi	Buy @ P 1.9¢	Sell @ K 5.5¢	+3.60%	+3.53%	Yes	P ↗︎ K ↗︎
JBP J.B. Pritzker	Polymarket → Kalshi	Buy @ P 1.7¢	Sell @ K 3.9¢	+2.20%	+2.13%	Yes	P ↗︎ K ↗︎
MK Mark Kelly	Polymarket → Kalshi	Buy @ P 1.8¢	Sell @ K 3.3¢	+1.50%	+1.43%	No	P ↗︎ K ↗︎
PB Pete Buttigieg	Polymarket → Kalshi	Buy @ P 4.4¢	Sell @ K 5.4¢	+1.00%	+0.93%	No	P ↗︎ K ↗︎
GN Gavin Newsom California Governor	Kalshi → Polymarket	Buy @ K 22¢	Sell @ P 23.1¢	+1.10%	+0.88%	No	K ↗︎ P ↗︎
JO Jon Ossoff	Polymarket → Kalshi	Buy @ P 7.8¢	Sell @ K 8.7¢	+0.90%	+0.81%	No	P ↗︎ K ↗︎
DJ Dwayne Johnson	Kalshi → Polymarket	Buy @ K 0.4¢	Sell @ P 1.2¢	+0.80%	+0.73%	No	K ↗︎ P ↗︎
AOC Alexandria Ocasio-Cortez NY Representative	Polymarket → Kalshi	Buy @ P 8.9¢	Sell @ K 9.7¢	+0.80%	+0.70%	No	P ↗︎ K ↗︎
WM Wes Moore	Polymarket → Kalshi	Buy @ P 1.4¢	Sell @ K 2.1¢	+0.70%	+0.63%	No	P ↗︎ K ↗︎
AB Andy Beshear	Polymarket → Kalshi	Buy @ P 2.8¢	Sell @ K 3.4¢	+0.60%	+0.53%	No	P ↗︎ K ↗︎
LC Liz Cheney	Kalshi → Polymarket	Buy @ K 0.1¢	Sell @ P 0.7¢	+0.60%	+0.53%	No	K ↗︎ P ↗︎
RC Roy Cooper	Kalshi → Polymarket	Buy @ K 0.3¢	Sell @ P 0.9¢	+0.60%	+0.53%	No	K ↗︎ P ↗︎
RK Ro Khanna	Polymarket → Kalshi	Buy @ P 1.9¢	Sell @ K 2.4¢	+0.50%	+0.43%	No	P ↗︎ K ↗︎
JF John Fetterman	Kalshi → Polymarket	Buy @ K 0.3¢	Sell @ P 0.8¢	+0.50%	+0.43%	No	K ↗︎ P ↗︎
BO Barack Obama	Kalshi → Polymarket	Buy @ K 0.2¢	Sell @ P 0.7¢	+0.50%	+0.43%	No	K ↗︎ P ↗︎
LJ Lebron James	Kalshi → Polymarket	Buy @ K 0.2¢	Sell @ P 0.7¢	+0.50%	+0.43%	No	K ↗︎ P ↗︎
HC Hilary Clinton	Kalshi → Polymarket	Buy @ K 0.2¢	Sell @ P 0.7¢	+0.50%	+0.43%	No	K ↗︎ P ↗︎
PM Phil Murphy	Kalshi → Polymarket	Buy @ K 0.1¢	Sell @ P 0.6¢	+0.50%	+0.43%	No	K ↗︎ P ↗︎
TW Tim Walz	Kalshi → Polymarket	Buy @ K 0.1¢	Sell @ P 0.6¢	+0.50%	+0.43%	No	K ↗︎ P ↗︎
GR Gina Raimondo	Kalshi → Polymarket	Buy @ K 0.3¢	Sell @ P 0.7¢	+0.40%	+0.33%	No	K ↗︎ P ↗︎
ZM Zohran Mamdani NYC Mayor	Kalshi → Polymarket	Buy @ K 0.3¢	Sell @ P 0.7¢	+0.40%	+0.33%	No	K ↗︎ P ↗︎
BS Bernie Sanders	Kalshi → Polymarket	Buy @ K 0.4¢	Sell @ P 0.7¢	+0.30%	+0.23%	No	K ↗︎ P ↗︎
JP Jared Polis	Kalshi → Polymarket	Buy @ K 0.4¢	Sell @ P 0.7¢	+0.30%	+0.23%	No	K ↗︎ P ↗︎
MO Michelle Obama	Polymarket → Kalshi	Buy @ P 1.4¢	Sell @ K 1.6¢	+0.20%	+0.13%	No	P ↗︎ K ↗︎
HB Hunter Biden	Polymarket → Kalshi	Buy @ P 0.9¢	Sell @ K 1.1¢	+0.20%	+0.13%	No	P ↗︎ K ↗︎
RW Raphael Warnock	Kalshi → Polymarket	Buy @ K 0.5¢	Sell @ P 0.7¢	+0.20%	+0.13%	No	K ↗︎ P ↗︎
CB Cory Booker	Kalshi → Polymarket	Buy @ K 0.7¢	Sell @ P 0.9¢	+0.20%	+0.13%	No	K ↗︎ P ↗︎
JS Jon Stewart Comedian	Polymarket → Kalshi	Buy @ P 1.7¢	Sell @ K 1.9¢	+0.20%	+0.13%	No	P ↗︎ K ↗︎
JS Josh Shapiro	Kalshi → Polymarket	Buy @ K 5¢	Sell @ P 5.2¢	+0.20%	+0.13%	No	K ↗︎ P ↗︎
SAS Stephen A. Smith	Kalshi → Polymarket	Buy @ K 0.9¢	Sell @ P 1¢	+0.10%	+0.03%	No	K ↗︎ P ↗︎
GW Gretchen Whitmer	Polymarket → Kalshi	Buy @ P 0.9¢	Sell @ K 1¢	+0.10%	+0.03%	No	P ↗︎ K ↗︎
CM Chris Murphy	Kalshi → Polymarket	Buy @ K 0.7¢	Sell @ P 0.8¢	+0.10%	+0.03%	No	K ↗︎ P ↗︎
RG Ruben Gallego	Kalshi → Polymarket	Buy @ K 0.8¢	Sell @ P 0.7¢	-0.10%	-0.17%	No	K ↗︎ P ↗︎
MC Mark Cuban	Kalshi → Polymarket	Buy @ K 1¢	Sell @ P 0.9¢	-0.10%	-0.17%	No	K ↗︎ P ↗︎
KH Kamala Harris	Polymarket → Kalshi	Buy @ P 7.7¢	Sell @ K 7.6¢	-0.10%	-0.18%	No	P ↗︎ K ↗︎

Outcome Diff

Outcome A	Outcome B	Venue	A Odds	B Odds	Diff	Strategy	Trade Now
GN Gavin Newsom	MK Mark Kelly	Polymarket	A 23.2%	B 1.8%	+21.45%	Buy spread	P ↗︎
GN Gavin Newsom	RE Rahm Emanuel	Polymarket	A 23.2%	B 1.8%	+21.35%	Buy spread	P ↗︎
GN Gavin Newsom	RK Ro Khanna	Polymarket	A 23.2%	B 1.8%	+21.35%	Buy spread	P ↗︎
GN Gavin Newsom	AB Andy Beshear	Polymarket	A 23.2%	B 2.8%	+20.45%	Buy spread	P ↗︎
GN Gavin Newsom	PB Pete Buttigieg	Polymarket	A 23.2%	B 4.4%	+18.85%	Buy spread	P ↗︎
GN Gavin Newsom	MK Mark Kelly	Kalshi	A 21.5%	B 3.4%	+18.10%	Buy spread	K ↗︎
GN Gavin Newsom	AB Andy Beshear	Kalshi	A 21.5%	B 3.5%	+18.00%	Buy spread	K ↗︎
GN Gavin Newsom	JS Josh Shapiro	Polymarket	A 23.2%	B 5.3%	+17.95%	Buy spread	P ↗︎
GN Gavin Newsom	JBP J.B. Pritzker	Kalshi	A 21.5%	B 4.0%	+17.55%	Buy spread	K ↗︎
GN Gavin Newsom	JS Josh Shapiro	Kalshi	A 21.5%	B 5.0%	+16.55%	Buy spread	K ↗︎
GN Gavin Newsom	PB Pete Buttigieg	Kalshi	A 21.5%	B 5.5%	+16.00%	Buy spread	K ↗︎
GN Gavin Newsom	RE Rahm Emanuel	Kalshi	A 21.5%	B 5.6%	+15.95%	Buy spread	K ↗︎
GN Gavin Newsom	KH Kamala Harris	Polymarket	A 23.2%	B 7.6%	+15.55%	Buy spread	P ↗︎
GN Gavin Newsom	JO Jon Ossoff	Polymarket	A 23.2%	B 7.8%	+15.45%	Buy spread	P ↗︎
GN Gavin Newsom	AOC Alexandria Ocasio-Cortez	Polymarket	A 23.2%	B 8.9%	+14.35%	Buy spread	P ↗︎
GN Gavin Newsom	KH Kamala Harris	Kalshi	A 21.5%	B 7.6%	+13.85%	Buy spread	K ↗︎
GN Gavin Newsom	JO Jon Ossoff	Kalshi	A 21.5%	B 8.8%	+12.70%	Buy spread	K ↗︎
GN Gavin Newsom	AOC Alexandria Ocasio-Cortez	Kalshi	A 21.5%	B 9.8%	+11.75%	Buy spread	K ↗︎
AOC Alexandria Ocasio-Cortez	MK Mark Kelly	Polymarket	A 8.9%	B 1.8%	+7.10%	Buy spread	P ↗︎
AOC Alexandria Ocasio-Cortez	RE Rahm Emanuel	Polymarket	A 8.9%	B 1.8%	+7.00%	Buy spread	P ↗︎
AOC Alexandria Ocasio-Cortez	RK Ro Khanna	Polymarket	A 8.9%	B 1.8%	+7.00%	Buy spread	P ↗︎
AOC Alexandria Ocasio-Cortez	MK Mark Kelly	Kalshi	A 9.8%	B 3.4%	+6.35%	Buy spread	K ↗︎
AOC Alexandria Ocasio-Cortez	AB Andy Beshear	Kalshi	A 9.8%	B 3.5%	+6.25%	Buy spread	K ↗︎
AOC Alexandria Ocasio-Cortez	AB Andy Beshear	Polymarket	A 8.9%	B 2.8%	+6.10%	Buy spread	P ↗︎
JO Jon Ossoff	MK Mark Kelly	Polymarket	A 7.8%	B 1.8%	+6.00%	Buy spread	P ↗︎
JO Jon Ossoff	RE Rahm Emanuel	Polymarket	A 7.8%	B 1.8%	+5.90%	Buy spread	P ↗︎
JO Jon Ossoff	RK Ro Khanna	Polymarket	A 7.8%	B 1.8%	+5.90%	Buy spread	P ↗︎
KH Kamala Harris	MK Mark Kelly	Polymarket	A 7.6%	B 1.8%	+5.90%	Buy spread	P ↗︎
AOC Alexandria Ocasio-Cortez	JBP J.B. Pritzker	Kalshi	A 9.8%	B 4.0%	+5.80%	Buy spread	K ↗︎
KH Kamala Harris	RE Rahm Emanuel	Polymarket	A 7.6%	B 1.8%	+5.80%	Buy spread	P ↗︎

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