Prediction Markets 2028 Democratic Presidential Nominee

2028 Democratic Presidential Nominee Odds

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Updated 40 minutes ago · 4:43 PM PDT

Jon Ossoff leads the 2028 Democratic nomination at 16.3%, 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 16.2% chance, still weighing a presidential run against a 2028 Senate primary challenge to Chuck Schumer. Gavin Newsom rounds out the top three at 14.2% 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

3.14%

Alexandria Ocasio-Cortez → View arbs

Current Favorite

16.3%

Jon Ossoff +12.8%

24H Volume (Share)

$679.8K

Momentum Leader

+12.8%

Jon Ossoff YTD change

Current Odds Snapshot

Current probabilities across platforms with liquidity indicators

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Jon Ossoff

Vol $6.5K Spread 0.4%

Agg 16.3%

↑ +12.8%

K 16.5%

G 16.5%

P 16.2%

AOC

Alexandria Ocasio-Cortez

Vol $21.1K Spread 3.9%

Agg 16.2%

↑ +4.3%

NY Representative

P 19.4%

G 17.5%

F 17.0%

K 15.5%

Gavin Newsom

Vol $56.3K Spread 8.5%

Agg 14.2%

↓ -21.2%

California Governor

F 22.0%

G 14.5%

P 14.4%

K 13.5%

Vol $42.8K 14.3–14.5¢

Kalshi 13.5%

Vol $13.5K 13–14¢

Kamala Harris

Vol $1.3K Spread 2.5%

Agg 8.1%

↑ +4.1%

G 8.5%

K 8.1%

P 7.9%

F 6.0%

Pete Buttigieg

Vol $3.1K Spread 5.6%

Agg 5.5%

↑ +1.0%

F 11.0%

P 5.7%

G 5.5%

K 5.5%

Josh Shapiro

Vol $11.4K Spread 3.4%

Agg 4.7%

↑ +0.5%

F 8.0%

P 6.4%

G 5.5%

K 4.7%

Mark Kelly

Vol $175.4K Spread 1.2%

Agg 3.6%

↑ +1.8%

K 3.8%

P 3.1%

G 2.5%

Andy Beshear

Vol $4.8K Spread 2.4%

Agg 3.4%

↑ +0.8%

F 5.0%

G 3.5%

K 3.5%

P 2.7%

Rahm Emanuel

Vol $5.3K Spread 1.0%

Agg 2.8%

↑ +0.9%

G 3.5%

K 3.5%

P 2.6%

Wes Moore

Vol $17.8K Spread 3.5%

Agg 2.2%

↓ -0.2%

F 5.0%

G 2.5%

K 2.3%

P 1.6%

Michelle Obama

Vol $3.7K Spread 1.9%

Agg 2.1%

↑ +1.1%

K 2.1%

P 0.3%

James Talarico

Vol $9.4K Spread —

Agg 1.8%

↑ +1.3%

K 1.8%

Kalshi 1.8%

Vol $9.4K 1.8–1.9¢

Ro Khanna

Vol $4.0K Spread 0.1%

Agg 1.8%

↑ +0.6%

K 1.8%

P 1.8%

JBP

J.B. Pritzker

Vol $45.3K Spread 2.8%

Agg 1.3%

↓ -0.7%

F 4.0%

G 1.5%

P 1.4%

K 1.3%

Dwayne Johnson

Vol $4.3K Spread 1.0%

Agg 1.1%

↓ -0.2%

P 1.1%

K 0.1%

Raphael Warnock

Vol $5.0K Spread 0.3%

Agg 0.8%

↑ +0.2%

K 0.9%

P 0.5%

Cory Booker

Vol $47.1K Spread 0.0%

Agg 0.6%

— +0.0%

P 0.7%

K 0.6%

Chelsea Clinton

Vol $808 Spread —

Agg 0.6%

↑ +0.1%

P 0.6%

Polymarket 0.6%

Vol $808 0.5–0.7¢

Gretchen Whitmer

Vol $11.8K Spread 3.5%

Agg 0.5%

↓ -1.4%

F 4.0%

G 1.5%

K 0.8%

P 0.5%

Hunter Biden

Vol $14.6K Spread 0.2%

Agg 0.5%

↓ -0.1%

P 0.5%

K 0.4%

Chris Murphy

Vol $45 Spread 0.1%

Agg 0.5%

↓ -0.2%

K 0.5%

P 0.4%

Elissa Slotkin

Vol $0 Spread —

Agg 0.4%

↓ -0.1%

K 0.4%

Kalshi 0.4%

Vol $0 0.4–0.5¢

Bernie Sanders

Vol $1.4K Spread 0.1%

Agg 0.3%

↓ -0.2%

P 0.4%

K 0.3%

Ruben Gallego

Vol $1.3K Spread 0.3%

Agg 0.3%

↓ -0.8%

K 0.4%

P 0.2%

Mark Cuban

Vol $37.5K Spread 0.9%

Agg 0.3%

↓ -0.5%

K 1.0%

P 0.1%

Jamie Dimon

Vol $603 Spread —

Agg 0.3%

↓ -0.3%

K 0.3%

Kalshi 0.3%

Vol $603 0.2–0.3¢

Barack Obama

Vol $246 Spread 0.1%

Agg 0.2%

↓ -0.4%

P 0.3%

K 0.2%

Zohran Mamdani

Vol $20.7K Spread 0.1%

Agg 0.2%

↓ -0.4%

NYC Mayor

P 0.3%

K 0.2%

Roy Cooper

Vol $7.5K Spread 0.2%

Agg 0.2%

↓ -0.5%

K 0.3%

P 0.2%

Andrew Yang

Vol $231 Spread —

Agg 0.2%

↓ -0.4%

P 0.2%

Polymarket 0.2%

Vol $231 0.1–0.2¢

Hilary Clinton

Vol $1.5K Spread 0.0%

Agg 0.2%

↓ -0.4%

K 0.2%

P 0.2%

Jared Polis

Vol $2.9K Spread 0.1%

Agg 0.2%

↓ -0.8%

P 0.2%

K 0.1%

Jasmine Crockett

Vol $13 Spread —

Agg 0.2%

↓ -0.4%

P 0.2%

Polymarket 0.2%

Vol $13 0.3¢

John Fetterman

Vol $14.3K Spread 0.1%

Agg 0.2%

↓ -1.1%

K 0.2%

P 0.1%

Gina Raimondo

Vol $3.6K Spread 0.1%

Agg 0.1%

↓ -0.3%

P 0.2%

K 0.1%

Jon Stewart

Vol $60.9K Spread 0.4%

Agg 0.1%

↓ -0.8%

Comedian

K 0.4%

P 0.1%

MrBeast

Vol $0 Spread —

Agg 0.1%

↓ -0.4%

P 0.1%

Polymarket 0.1%

Vol $0 0.2¢

SAS

Stephen A. Smith

Vol $27.2K Spread 0.3%

Agg 0.1%

↓ -0.7%

K 0.4%

P 0.1%

BOR

Beto O’Rourke

Vol $47 Spread —

Agg 0.1%

↓ -0.8%

P 0.1%

Polymarket 0.1%

Vol $47 0.1¢

George Clooney

Vol $50.2K Spread —

Agg 0.1%

↓ -0.5%

P 0.1%

Polymarket 0.1%

Vol $50.2K 0.1¢

Kim Kardashian

Vol $56 Spread —

Agg 0.1%

↓ -0.6%

P 0.1%

Polymarket 0.1%

Vol $56 0.1¢

Lebron James

Vol $80 Spread 0.0%

Agg 0.1%

↓ -0.8%

K 0.1%

P 0.1%

Liz Cheney

Vol $0 Spread 0.0%

Agg 0.1%

↓ -0.5%

K 0.1%

P 0.1%

Oprah Winfrey

Vol $355 Spread —

Agg 0.1%

↓ -0.4%

P 0.1%

Polymarket 0.1%

Vol $355 0.1¢

Phil Murphy

Vol $52 Spread 0.0%

Agg 0.1%

↓ -0.5%

K 0.1%

P 0.1%

Tim Walz

Vol $133 Spread 0.0%

Agg 0.1%

↓ -0.5%

K 0.1%

P 0.1%

Outcome	Aggregated	Spread	Volume	Kalshi	Polymarket	Gemini	ForecastEx
JO Jon Ossoff	16.3% ↑ +12.8%	0.4%	$6.5K	Kalshi 16.5% 16–17¢ Vol $3.4K	Polymarket 16.2% 16.1–16.2¢ Vol $3.1K	Gemini 16.5% 16–17¢ Vol $0	ForecastEx — —
AOC Alexandria Ocasio-Cortez NY Representative	16.2% ↑ +4.3%	3.9%	$21.1K	Kalshi 15.5% 15–16¢ Vol $17.5K	Polymarket 19.4% 19.3–19.4¢ Vol $3.6K	Gemini 17.5% 17–18¢ Vol $3	ForecastEx 17.0% 17¢ Vol $0
GN Gavin Newsom California Governor	14.2% ↓ -21.2%	8.5%	$56.3K	Kalshi 13.5% 13–14¢ Vol $13.5K	Polymarket 14.4% 14.3–14.5¢ Vol $42.8K	Gemini 14.5% 14–15¢ Vol $22	ForecastEx 22.0% 22¢ Vol $1
KH Kamala Harris	8.1% ↑ +4.1%	2.5%	$1.3K	Kalshi 8.1% 8–8.2¢ Vol $1.1K	Polymarket 7.9% 7.8–7.9¢ Vol $175	Gemini 8.5% 8–9¢ Vol $0	ForecastEx 6.0% 6¢ Vol $0
PB Pete Buttigieg	5.5% ↑ +1.0%	5.6%	$3.1K	Kalshi 5.5% 5.4–5.5¢ Vol $3.0K	Polymarket 5.7% 5.6–5.7¢ Vol $113	Gemini 5.5% 5–6¢ Vol $2	ForecastEx 11.0% 11¢ Vol $0
JS Josh Shapiro	4.7% ↑ +0.5%	3.4%	$11.4K	Kalshi 4.7% 4.6–4.7¢ Vol $11.3K	Polymarket 6.4% 6.3–6.4¢ Vol $86	Gemini 5.5% 5–6¢ Vol $0	ForecastEx 8.0% 8¢ Vol $0
MK Mark Kelly	3.6% ↑ +1.8%	1.2%	$175.4K	Kalshi 3.8% 3.6–3.9¢ Vol $134.5K	Polymarket 3.1% 3–3.1¢ Vol $40.9K	Gemini 2.5% 2–3¢ Vol $48	ForecastEx — —
AB Andy Beshear	3.4% ↑ +0.8%	2.4%	$4.8K	Kalshi 3.5% 3.4–3.5¢ Vol $4.6K	Polymarket 2.7% 2.6–2.7¢ Vol $188	Gemini 3.5% 3–4¢ Vol $4	ForecastEx 5.0% 5¢ Vol $0
RE Rahm Emanuel	2.8% ↑ +0.9%	1.0%	$5.3K	Kalshi 3.5% 3.4–3.5¢ Vol $1.7K	Polymarket 2.6% 2.5–2.6¢ Vol $3.5K	Gemini 3.5% 3–4¢ Vol $0	ForecastEx — —
WM Wes Moore	2.2% ↓ -0.2%	3.5%	$17.8K	Kalshi 2.3% 2.2–2.3¢ Vol $17.7K	Polymarket 1.6% 1.5–1.6¢ Vol $88	Gemini 2.5% 2–3¢ Vol $0	ForecastEx 5.0% 5¢ Vol $0
MO Michelle Obama	2.1% ↑ +1.1%	1.9%	$3.7K	Kalshi 2.1% 2–2.2¢ Vol $3.7K	Polymarket 0.3% 0.2–0.3¢ Vol $15	Gemini — —	ForecastEx — —
JT James Talarico	1.8% ↑ +1.3%	—	$9.4K	Kalshi 1.8% 1.8–1.9¢ Vol $9.4K	Polymarket — —	Gemini — —	ForecastEx — —
RK Ro Khanna	1.8% ↑ +0.6%	0.1%	$4.0K	Kalshi 1.8% 1.8–1.9¢ Vol $3.2K	Polymarket 1.8% 1.7–1.8¢ Vol $854	Gemini — —	ForecastEx — —
JBP J.B. Pritzker	1.3% ↓ -0.7%	2.8%	$45.3K	Kalshi 1.3% 1.2–1.3¢ Vol $412	Polymarket 1.4% 1.2–1.5¢ Vol $44.9K	Gemini 1.5% 1–2¢ Vol $0	ForecastEx 4.0% 4¢ Vol $0
DJ Dwayne Johnson	1.1% ↓ -0.2%	1.0%	$4.3K	Kalshi 0.1% 0–0.2¢ Vol $0	Polymarket 1.1% 1–1.2¢ Vol $4.3K	Gemini — —	ForecastEx — —
RW Raphael Warnock	0.8% ↑ +0.2%	0.3%	$5.0K	Kalshi 0.9% 0.8–0.9¢ Vol $3.7K	Polymarket 0.5% 0.5–0.6¢ Vol $1.3K	Gemini — —	ForecastEx — —
CB Cory Booker	0.6% — +0.0%	0.0%	$47.1K	Kalshi 0.6% 0.5–0.7¢ Vol $17.1K	Polymarket 0.7% 0.6–0.7¢ Vol $30.0K	Gemini — —	ForecastEx — —
CC Chelsea Clinton	0.6% ↑ +0.1%	—	$808	Kalshi — —	Polymarket 0.6% 0.5–0.7¢ Vol $808	Gemini — —	ForecastEx — —
GW Gretchen Whitmer	0.5% ↓ -1.4%	3.5%	$11.8K	Kalshi 0.8% 0.7–0.8¢ Vol $6	Polymarket 0.5% 0.4–0.6¢ Vol $11.8K	Gemini 1.5% 1–2¢ Vol $0	ForecastEx 4.0% 4¢ Vol $0
HB Hunter Biden	0.5% ↓ -0.1%	0.2%	$14.6K	Kalshi 0.4% 0.3–0.4¢ Vol $3.6K	Polymarket 0.5% 0.4–0.6¢ Vol $11.0K	Gemini — —	ForecastEx — —
CM Chris Murphy	0.5% ↓ -0.2%	0.1%	$45	Kalshi 0.5% 0.5–0.6¢ Vol $5	Polymarket 0.4% 0.4–0.5¢ Vol $40	Gemini — —	ForecastEx — —
ES Elissa Slotkin	0.4% ↓ -0.1%	—	$0	Kalshi 0.4% 0.4–0.5¢ Vol $0	Polymarket — —	Gemini — —	ForecastEx — —
BS Bernie Sanders	0.3% ↓ -0.2%	0.1%	$1.4K	Kalshi 0.3% 0.2–0.3¢ Vol $796	Polymarket 0.4% 0.3–0.4¢ Vol $641	Gemini — —	ForecastEx — —
RG Ruben Gallego	0.3% ↓ -0.8%	0.3%	$1.3K	Kalshi 0.4% 0.4–0.5¢ Vol $623	Polymarket 0.2% 0.1–0.2¢ Vol $677	Gemini — —	ForecastEx — —
MC Mark Cuban	0.3% ↓ -0.5%	0.9%	$37.5K	Kalshi 1.0% 0.9–1¢ Vol $7.7K	Polymarket 0.1% 0.2¢ Vol $29.8K	Gemini — —	ForecastEx — —
JD Jamie Dimon	0.3% ↓ -0.3%	—	$603	Kalshi 0.3% 0.2–0.3¢ Vol $603	Polymarket — —	Gemini — —	ForecastEx — —
BO Barack Obama	0.2% ↓ -0.4%	0.1%	$246	Kalshi 0.2% 0.1–0.3¢ Vol $7	Polymarket 0.3% 0.2–0.3¢ Vol $238	Gemini — —	ForecastEx — —
ZM Zohran Mamdani NYC Mayor	0.2% ↓ -0.4%	0.1%	$20.7K	Kalshi 0.2% 0.1–0.2¢ Vol $20.1K	Polymarket 0.3% 0.2–0.3¢ Vol $594	Gemini — —	ForecastEx — —
RC Roy Cooper	0.2% ↓ -0.5%	0.2%	$7.5K	Kalshi 0.3% 0.2–0.4¢ Vol $5	Polymarket 0.2% 0.1–0.2¢ Vol $7.5K	Gemini — —	ForecastEx — —
AY Andrew Yang	0.2% ↓ -0.4%	—	$231	Kalshi — —	Polymarket 0.2% 0.1–0.2¢ Vol $231	Gemini — —	ForecastEx — —
HC Hilary Clinton	0.2% ↓ -0.4%	0.0%	$1.5K	Kalshi 0.2% 0.1–0.2¢ Vol $0	Polymarket 0.2% 0.1–0.2¢ Vol $1.5K	Gemini — —	ForecastEx — —
JP Jared Polis	0.2% ↓ -0.8%	0.1%	$2.9K	Kalshi 0.1% 0–0.1¢ Vol $1	Polymarket 0.2% 0.1–0.2¢ Vol $2.9K	Gemini — —	ForecastEx — —
JC Jasmine Crockett	0.2% ↓ -0.4%	—	$13	Kalshi — —	Polymarket 0.2% 0.3¢ Vol $13	Gemini — —	ForecastEx — —
JF John Fetterman	0.2% ↓ -1.1%	0.1%	$14.3K	Kalshi 0.2% 0.1–0.2¢ Vol $14.3K	Polymarket 0.1% 0.1¢ Vol $0	Gemini — —	ForecastEx — —
GR Gina Raimondo	0.1% ↓ -0.3%	0.1%	$3.6K	Kalshi 0.1% 0–0.1¢ Vol $94	Polymarket 0.2% 0.1–0.2¢ Vol $3.5K	Gemini — —	ForecastEx — —
JS Jon Stewart Comedian	0.1% ↓ -0.8%	0.4%	$60.9K	Kalshi 0.4% 0.4–0.5¢ Vol $203	Polymarket 0.1% 0.2¢ Vol $60.7K	Gemini — —	ForecastEx — —
MR MrBeast	0.1% ↓ -0.4%	—	$0	Kalshi — —	Polymarket 0.1% 0.2¢ Vol $0	Gemini — —	ForecastEx — —
SAS Stephen A. Smith	0.1% ↓ -0.7%	0.3%	$27.2K	Kalshi 0.4% 0.3–0.4¢ Vol $4.3K	Polymarket 0.1% 0.1¢ Vol $22.9K	Gemini — —	ForecastEx — —
BOR Beto O’Rourke	0.1% ↓ -0.8%	—	$47	Kalshi — —	Polymarket 0.1% 0.1¢ Vol $47	Gemini — —	ForecastEx — —
GC George Clooney	0.1% ↓ -0.5%	—	$50.2K	Kalshi — —	Polymarket 0.1% 0.1¢ Vol $50.2K	Gemini — —	ForecastEx — —
KK Kim Kardashian	0.1% ↓ -0.6%	—	$56	Kalshi — —	Polymarket 0.1% 0.1¢ Vol $56	Gemini — —	ForecastEx — —
LJ Lebron James	0.1% ↓ -0.8%	0.0%	$80	Kalshi 0.1% 0–0.1¢ Vol $3	Polymarket 0.1% 0.1¢ Vol $78	Gemini — —	ForecastEx — —
LC Liz Cheney	0.1% ↓ -0.5%	0.0%	$0	Kalshi 0.1% 0–0.1¢ Vol $0	Polymarket 0.1% 0.1¢ Vol $0	Gemini — —	ForecastEx — —
OW Oprah Winfrey	0.1% ↓ -0.4%	—	$355	Kalshi — —	Polymarket 0.1% 0.1¢ Vol $355	Gemini — —	ForecastEx — —
PM Phil Murphy	0.1% ↓ -0.5%	0.0%	$52	Kalshi 0.1% 0–0.1¢ Vol $0	Polymarket 0.1% 0.1¢ Vol $52	Gemini — —	ForecastEx — —
TW Tim Walz	0.1% ↓ -0.5%	0.0%	$133	Kalshi 0.1% 0–0.1¢ Vol $1	Polymarket 0.1% 0.1¢ Vol $132	Gemini — —	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
AOC Alexandria Ocasio-Cortez NY Representative	Kalshi → Polymarket	Buy @ K 16¢	Sell @ P 19.3¢	+3.30%	+3.14%	Yes	K ↗︎ P ↗︎
MO Michelle Obama	Polymarket → Kalshi	Buy @ P 0.3¢	Sell @ K 2¢	+1.70%	+1.63%	Yes	P ↗︎ K ↗︎
JS Josh Shapiro	Kalshi → Polymarket	Buy @ K 4.7¢	Sell @ P 6.3¢	+1.60%	+1.53%	Yes	K ↗︎ P ↗︎
RE Rahm Emanuel	Polymarket → Kalshi	Buy @ P 2.6¢	Sell @ K 3.4¢	+0.80%	+0.73%	No	P ↗︎ K ↗︎
DJ Dwayne Johnson	Kalshi → Polymarket	Buy @ K 0.2¢	Sell @ P 1¢	+0.80%	+0.73%	No	K ↗︎ P ↗︎
AB Andy Beshear	Polymarket → Kalshi	Buy @ P 2.7¢	Sell @ K 3.4¢	+0.70%	+0.63%	No	P ↗︎ K ↗︎
MC Mark Cuban	Polymarket → Kalshi	Buy @ P 0.2¢	Sell @ K 0.9¢	+0.70%	+0.63%	No	P ↗︎ K ↗︎
WM Wes Moore	Polymarket → Kalshi	Buy @ P 1.6¢	Sell @ K 2.2¢	+0.60%	+0.53%	No	P ↗︎ K ↗︎
MK Mark Kelly	Gemini → Kalshi	Buy @ G 3¢	Sell @ K 3.6¢	+0.60%	+0.52%	No	G ↗︎ K ↗︎
GW Gretchen Whitmer	Polymarket → Gemini	Buy @ P 0.6¢	Sell @ G 1¢	+0.40%	+0.40%	No	P ↗︎ G ↗︎
GN Gavin Newsom California Governor	Kalshi → Polymarket	Buy @ K 14¢	Sell @ P 14.3¢	+0.30%	+0.16%	No	K ↗︎ P ↗︎
RW Raphael Warnock	Polymarket → Kalshi	Buy @ P 0.6¢	Sell @ K 0.8¢	+0.20%	+0.13%	No	P ↗︎ K ↗︎
RG Ruben Gallego	Polymarket → Kalshi	Buy @ P 0.2¢	Sell @ K 0.4¢	+0.20%	+0.13%	No	P ↗︎ K ↗︎
JS Jon Stewart Comedian	Polymarket → Kalshi	Buy @ P 0.2¢	Sell @ K 0.4¢	+0.20%	+0.13%	No	P ↗︎ K ↗︎
SAS Stephen A. Smith	Polymarket → Kalshi	Buy @ P 0.1¢	Sell @ K 0.3¢	+0.20%	+0.13%	No	P ↗︎ K ↗︎
KH Kamala Harris	Polymarket → Gemini	Buy @ P 7.9¢	Sell @ G 8¢	+0.10%	+0.07%	No	P ↗︎ G ↗︎
PB Pete Buttigieg	Kalshi → Polymarket	Buy @ K 5.5¢	Sell @ P 5.6¢	+0.10%	+0.03%	No	K ↗︎ P ↗︎
RK Ro Khanna	Polymarket → Kalshi	Buy @ P 1.8¢	Sell @ K 1.8¢	+0.00%	-0.07%	No	P ↗︎ K ↗︎
HB Hunter Biden	Kalshi → Polymarket	Buy @ K 0.4¢	Sell @ P 0.4¢	+0.00%	-0.07%	No	K ↗︎ P ↗︎
CM Chris Murphy	Polymarket → Kalshi	Buy @ P 0.5¢	Sell @ K 0.5¢	+0.00%	-0.07%	No	P ↗︎ K ↗︎
BS Bernie Sanders	Kalshi → Polymarket	Buy @ K 0.3¢	Sell @ P 0.3¢	+0.00%	-0.07%	No	K ↗︎ P ↗︎
ZM Zohran Mamdani NYC Mayor	Kalshi → Polymarket	Buy @ K 0.2¢	Sell @ P 0.2¢	+0.00%	-0.07%	No	K ↗︎ P ↗︎
RC Roy Cooper	Polymarket → Kalshi	Buy @ P 0.2¢	Sell @ K 0.2¢	+0.00%	-0.07%	No	P ↗︎ K ↗︎
JP Jared Polis	Kalshi → Polymarket	Buy @ K 0.1¢	Sell @ P 0.1¢	+0.00%	-0.07%	No	K ↗︎ P ↗︎
JF John Fetterman	Polymarket → Kalshi	Buy @ P 0.1¢	Sell @ K 0.1¢	+0.00%	-0.07%	No	P ↗︎ K ↗︎
GR Gina Raimondo	Kalshi → Polymarket	Buy @ K 0.1¢	Sell @ P 0.1¢	+0.00%	-0.07%	No	K ↗︎ P ↗︎
LJ Lebron James	Polymarket → Kalshi	Buy @ P 0.1¢	Sell @ K 0¢	-0.10%	-0.10%	No	P ↗︎ K ↗︎
LC Liz Cheney	Polymarket → Kalshi	Buy @ P 0.1¢	Sell @ K 0¢	-0.10%	-0.10%	No	P ↗︎ K ↗︎
PM Phil Murphy	Polymarket → Kalshi	Buy @ P 0.1¢	Sell @ K 0¢	-0.10%	-0.10%	No	P ↗︎ K ↗︎
TW Tim Walz	Polymarket → Kalshi	Buy @ P 0.1¢	Sell @ K 0¢	-0.10%	-0.10%	No	P ↗︎ K ↗︎
JBP J.B. Pritzker	Kalshi → Polymarket	Buy @ K 1.3¢	Sell @ P 1.2¢	-0.10%	-0.17%	No	K ↗︎ P ↗︎
CB Cory Booker	Kalshi → Polymarket	Buy @ K 0.7¢	Sell @ P 0.6¢	-0.10%	-0.17%	No	K ↗︎ P ↗︎
BO Barack Obama	Kalshi → Polymarket	Buy @ K 0.3¢	Sell @ P 0.2¢	-0.10%	-0.17%	No	K ↗︎ P ↗︎
HC Hilary Clinton	Kalshi → Polymarket	Buy @ K 0.2¢	Sell @ P 0.1¢	-0.10%	-0.17%	No	K ↗︎ P ↗︎
JO Jon Ossoff	Polymarket → Gemini	Buy @ P 16.2¢	Sell @ G 16¢	-0.20%	-0.26%	No	P ↗︎ G ↗︎

Outcome Diff

Outcome A	Outcome B	Venue	A Odds	B Odds	Diff	Strategy	Trade Now
AOC Alexandria Ocasio-Cortez	RK Ro Khanna	Polymarket	A 19.4%	B 1.8%	+17.60%	Buy spread	P ↗︎
AOC Alexandria Ocasio-Cortez	RE Rahm Emanuel	Polymarket	A 19.4%	B 2.6%	+16.80%	Buy spread	P ↗︎
AOC Alexandria Ocasio-Cortez	AB Andy Beshear	Polymarket	A 19.4%	B 2.7%	+16.70%	Buy spread	P ↗︎
AOC Alexandria Ocasio-Cortez	MK Mark Kelly	Polymarket	A 19.4%	B 3.1%	+16.30%	Buy spread	P ↗︎
AOC Alexandria Ocasio-Cortez	MK Mark Kelly	Gemini	A 17.5%	B 2.5%	+15.00%	Buy spread	G ↗︎
AOC Alexandria Ocasio-Cortez	WM Wes Moore	Gemini	A 17.5%	B 2.5%	+15.00%	Buy spread	G ↗︎
JO Jon Ossoff	RK Ro Khanna	Polymarket	A 16.2%	B 1.8%	+14.40%	Buy spread	P ↗︎
JO Jon Ossoff	WM Wes Moore	Kalshi	A 16.5%	B 2.3%	+14.25%	Buy spread	K ↗︎
JO Jon Ossoff	MK Mark Kelly	Gemini	A 16.5%	B 2.5%	+14.00%	Buy spread	G ↗︎
JO Jon Ossoff	WM Wes Moore	Gemini	A 16.5%	B 2.5%	+14.00%	Buy spread	G ↗︎
AOC Alexandria Ocasio-Cortez	AB Andy Beshear	Gemini	A 17.5%	B 3.5%	+14.00%	Buy spread	G ↗︎
AOC Alexandria Ocasio-Cortez	RE Rahm Emanuel	Gemini	A 17.5%	B 3.5%	+14.00%	Buy spread	G ↗︎
AOC Alexandria Ocasio-Cortez	PB Pete Buttigieg	Polymarket	A 19.4%	B 5.7%	+13.70%	Buy spread	P ↗︎
JO Jon Ossoff	RE Rahm Emanuel	Polymarket	A 16.2%	B 2.6%	+13.60%	Buy spread	P ↗︎
JO Jon Ossoff	AB Andy Beshear	Polymarket	A 16.2%	B 2.7%	+13.50%	Buy spread	P ↗︎
AOC Alexandria Ocasio-Cortez	WM Wes Moore	Kalshi	A 15.5%	B 2.3%	+13.25%	Buy spread	K ↗︎
JO Jon Ossoff	MK Mark Kelly	Polymarket	A 16.2%	B 3.1%	+13.10%	Buy spread	P ↗︎
JO Jon Ossoff	AB Andy Beshear	Kalshi	A 16.5%	B 3.5%	+13.05%	Buy spread	K ↗︎
JO Jon Ossoff	RE Rahm Emanuel	Kalshi	A 16.5%	B 3.5%	+13.05%	Buy spread	K ↗︎
AOC Alexandria Ocasio-Cortez	JS Josh Shapiro	Polymarket	A 19.4%	B 6.4%	+13.00%	Buy spread	P ↗︎
JO Jon Ossoff	AB Andy Beshear	Gemini	A 16.5%	B 3.5%	+13.00%	Buy spread	G ↗︎
JO Jon Ossoff	RE Rahm Emanuel	Gemini	A 16.5%	B 3.5%	+13.00%	Buy spread	G ↗︎
JO Jon Ossoff	MK Mark Kelly	Kalshi	A 16.5%	B 3.8%	+12.75%	Buy spread	K ↗︎
GN Gavin Newsom	RK Ro Khanna	Polymarket	A 14.4%	B 1.8%	+12.65%	Buy spread	P ↗︎
AOC Alexandria Ocasio-Cortez	AB Andy Beshear	Kalshi	A 15.5%	B 3.5%	+12.05%	Buy spread	K ↗︎
AOC Alexandria Ocasio-Cortez	RE Rahm Emanuel	Kalshi	A 15.5%	B 3.5%	+12.05%	Buy spread	K ↗︎
AOC Alexandria Ocasio-Cortez	PB Pete Buttigieg	Gemini	A 17.5%	B 5.5%	+12.00%	Buy spread	G ↗︎
AOC Alexandria Ocasio-Cortez	JS Josh Shapiro	Gemini	A 17.5%	B 5.5%	+12.00%	Buy spread	G ↗︎
GN Gavin Newsom	MK Mark Kelly	Gemini	A 14.5%	B 2.5%	+12.00%	Buy spread	G ↗︎
GN Gavin Newsom	WM Wes Moore	Gemini	A 14.5%	B 2.5%	+12.00%	Buy spread	G ↗︎

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).

Gemini: Public Prediction Markets + ticker endpoints (best bid/ask + last + 24H USD volume 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