Refreshed every 30 minutes

The same market, priced two ways

We find the events that trade on Polymarket, Kalshi, Robinhood and PredictIt at the same time, confirm they resolve on identical criteria, and lay both prices side by side. When the combined cost dips under $1, that is a live arbitrage: we flag it the moment it opens and leave it on the board so you can see we caught it. We do not trade it. If you want to, the legs are one tap away.

102 matched events across venues

9 with a live arbitrage right now

Who will be the Prime Minister of Israel after the 2026 election? — Benjamin Netanyahu

Kalshi / Robinhood vs PredictIt
Arb +62.1%
YES onKalshi / Robinhood
4¢
NO onPredictIt
58¢
Cost to lock $1: 62¢Locked profit: 38¢ per $1

French presidential election: who will advance? Will Marine Le Pen qualify for the runoff in the 2027 French presidential election?

Resolves Apr 17, 2028PredictIt vs Kalshi / Robinhood
Arb +35.1%
YES onPredictIt
50¢
NO onKalshi / Robinhood
24¢
Cost to lock $1: 74¢Locked profit: 26¢ per $1

Who will advance in the Brazilian presidential election? Luiz Inácio Lula da Silva

Resolves Oct 3, 2028PredictIt vs Kalshi / Robinhood
Arb +13.6%
YES onPredictIt
78¢
NO onKalshi / Robinhood
10¢
Cost to lock $1: 88¢Locked profit: 12¢ per $1

Will Congress override Trump's veto? Will Congress ever override Trump's veto?

Resolves Jan 20, 2029PredictIt vs Kalshi / Robinhood
Arb +6.4%
YES onPredictIt
23¢
NO onKalshi / Robinhood
71¢
Cost to lock $1: 94¢Locked profit: 6¢ per $1

Who will be the next Supreme Court justice? Will Emil Bove become the next Justice on the Supreme Court?

Resolves Feb 3, 2029Kalshi / Robinhood vs PredictIt
Arb +6.0%
YES onKalshi / Robinhood
5¢
NO onPredictIt
89¢
Cost to lock $1: 94¢Locked profit: 6¢ per $1

Who will win the 2028 US presidential election? — Gavin Newsom

Polymarket vs PredictIt
Arb +5.5%
YES onPolymarket
12¢
NO onPredictIt
83¢
Cost to lock $1: 95¢Locked profit: 5¢ per $1

Both markets are about Gavin Newsom winning the 2028 US Presidential Election.

French presidential election: who will advance? Will Jordan Bardella qualify for the runoff in the 2027 French presidential election?

Resolves Apr 17, 2028Kalshi / Robinhood vs PredictIt
Arb +4.2%
YES onKalshi / Robinhood
7¢
NO onPredictIt
89¢
Cost to lock $1: 96¢Locked profit: 4¢ per $1

2028 Democratic presidential nominee Will Rahm Emanuel be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Polymarket vs Kalshi / Robinhood
Arb +3.4%
YES onPolymarket
2¢
NO onKalshi / Robinhood
95¢
Cost to lock $1: 97¢Locked profit: 3¢ per $1

2028 Democratic presidential nominee Will Mark Kelly be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Polymarket vs PredictIt
Arb +3.1%
YES onPolymarket
1¢
NO onPredictIt
96¢
Cost to lock $1: 97¢Locked profit: 3¢ per $1

2028 Democratic presidential nominee Will Andy Beshear be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Polymarket vs PredictIt
Matched
YES onPolymarket
1¢
NO onPredictIt
96¢
Combined cost: 97¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Kamala Harris be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028PredictIt vs Kalshi / Robinhood
Arb 1d ago
YES onPredictIt
5¢
NO onKalshi / Robinhood
92¢
Combined cost: 97¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Ron DeSantis be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Polymarket vs Kalshi / Robinhood
Arb 2d ago
YES onPolymarket
3¢
NO onKalshi / Robinhood
95¢
Combined cost: 98¢ (over $1, no lock right now)

2028 Republican Presidential ticket Will JD Vance and Sarah Huckabee Sanders be the 2028 Republican Presidential ticket?

Resolves Nov 14, 2028Polymarket vs Kalshi / Robinhood
Matched
YES onPolymarket
1¢
NO onKalshi / Robinhood
97¢
Combined cost: 98¢ (over $1, no lock right now)

Who will leave Trump's Cabinet next? Will Howard Lutnick be the next person to leave the Trump Cabinet?

Resolves Jan 20, 2029Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
9¢
NO onPredictIt
89¢
Combined cost: 98¢ (over $1, no lock right now)

Who will be the next Supreme Court justice? Will Neomi Rao become the next Justice on the Supreme Court?

Resolves Feb 3, 2029Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
2¢
NO onPredictIt
96¢
Combined cost: 98¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Jon Ossoff be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Kalshi / Robinhood vs PredictIt
Arb 12h ago
YES onKalshi / Robinhood
15¢
NO onPredictIt
83¢
Combined cost: 98¢ (over $1, no lock right now)

Will Kamala Harris and Gavin Newsom be the two frontrunners for the 2028 Democratic Presidential Nomination?

Resolves Jun 1, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
19¢
NO onPredictIt
79¢
Combined cost: 98¢ (over $1, no lock right now)

Both markets are about Gavin Newsom winning the 2028 Democratic presidential nomination.

Who will be the next Supreme Court justice? Will Aileen Cannon become the next Justice on the Supreme Court?

Resolves Feb 3, 2029PredictIt vs Kalshi / Robinhood
Matched
YES onPredictIt
8¢
NO onKalshi / Robinhood
90¢
Combined cost: 98¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Nikki Haley be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
0¢
NO onPredictIt
98¢
Combined cost: 98¢ (over $1, no lock right now)

2028 Democratic VP nominee Will Ruben Gallego be the nominee for the Vice Presidency for the Democratic party?

Resolves Nov 7, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
2¢
NO onPredictIt
97¢
Combined cost: 99¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Gretchen Whitmer be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
1¢
NO onPredictIt
98¢
Combined cost: 99¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Brian Kemp be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Polymarket vs PredictIt
Matched
YES onPolymarket
1¢
NO onPredictIt
98¢
Combined cost: 99¢ (over $1, no lock right now)

2028 Republican Presidential ticket Will JD Vance and Glenn Youngkin be the 2028 Republican Presidential ticket?

Resolves Nov 14, 2028Polymarket vs PredictIt
Matched
YES onPolymarket
1¢
NO onPredictIt
98¢
Combined cost: 99¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Josh Shapiro be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
5¢
NO onPredictIt
94¢
Combined cost: 99¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Wes Moore be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Polymarket vs Kalshi / Robinhood
Matched
YES onPolymarket
1¢
NO onKalshi / Robinhood
98¢
Combined cost: 99¢ (over $1, no lock right now)

2028 Democratic Presidential ticket Will Jon Ossoff and Andy Beshear be the 2028 Democratic Presidential ticket?

Resolves Nov 14, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
2¢
NO onPredictIt
97¢
Combined cost: 99¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Alexandria Ocasio-Cortez be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028PredictIt vs Kalshi / Robinhood
Matched
YES onPredictIt
13¢
NO onKalshi / Robinhood
86¢
Combined cost: 99¢ (over $1, no lock right now)

2028 Republican Presidential ticket Will Ron DeSantis and JD Vance be the 2028 Republican Presidential ticket?

Resolves Nov 14, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
2¢
NO onPredictIt
97¢
Combined cost: 99¢ (over $1, no lock right now)

Who will leave Trump's Cabinet next? Will Russell Vought be the next person to leave the Trump Cabinet?

Resolves Jan 20, 2029Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
2¢
NO onPredictIt
97¢
Combined cost: 99¢ (over $1, no lock right now)

Who will be the next Supreme Court justice? Will Ted Cruz become the next Justice on the Supreme Court?

Resolves Feb 3, 2029Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
5¢
NO onPredictIt
94¢
Combined cost: 99¢ (over $1, no lock right now)

Who will be the next Supreme Court justice? Will Mike Lee become the next Justice on the Supreme Court?

Resolves Feb 3, 2029Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
3¢
NO onPredictIt
96¢
Combined cost: 99¢ (over $1, no lock right now)

Who will be the Prime Minister of Israel after the 2026 election? — Naftali Bennett

Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
20¢
NO onPredictIt
79¢
Combined cost: 99¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Stephen A. Smith be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Polymarket vs PredictIt
Matched
YES onPolymarket
0¢
NO onPredictIt
99¢
Combined cost: 99¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Jon Stewart be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Kalshi / Robinhood vs Polymarket
Matched
YES onKalshi / Robinhood
2¢
NO onPolymarket
98¢
Combined cost: 99¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Pete Hegseth be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
0¢
NO onPredictIt
99¢
Combined cost: 99¢ (over $1, no lock right now)

Who will be the next Supreme Court justice? Will Stuart Kyle Duncan become the next Justice on the Supreme Court?

Resolves Feb 3, 2029Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
0¢
NO onPredictIt
99¢
Combined cost: 99¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Tucker Carlson be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Polymarket vs PredictIt
Matched
YES onPolymarket
1¢
NO onPredictIt
98¢
Combined cost: 99¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Elon Musk be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Kalshi / Robinhood vs Polymarket
Matched
YES onKalshi / Robinhood
0¢
NO onPolymarket
99¢
Combined cost: 99¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Cory Booker be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Polymarket vs PredictIt
Matched
YES onPolymarket
1¢
NO onPredictIt
99¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Greg Abbott be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Kalshi / Robinhood vs Polymarket
Matched
YES onKalshi / Robinhood
0¢
NO onPolymarket
99¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Ruben Gallego be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
1¢
NO onPredictIt
99¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Tulsi Gabbard be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
1¢
NO onPredictIt
99¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Elissa Slotkin be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
1¢
NO onPredictIt
99¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Josh Hawley be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Polymarket vs Kalshi / Robinhood
Matched
YES onPolymarket
0¢
NO onKalshi / Robinhood
99¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Robert F. Kennedy Jr. be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Kalshi / Robinhood vs Polymarket
Matched
YES onKalshi / Robinhood
0¢
NO onPolymarket
99¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Roy Cooper be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Kalshi / Robinhood vs Polymarket
Matched
YES onKalshi / Robinhood
0¢
NO onPolymarket
99¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Byron Donalds be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Kalshi / Robinhood vs Polymarket
Matched
YES onKalshi / Robinhood
0¢
NO onPolymarket
99¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Republican VP nominee Will Ted Cruz be the nominee for the Vice Presidency for the Republican party?

Resolves Nov 7, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
2¢
NO onPredictIt
98¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Republican VP nominee Will Donald J. Trump Jr. be the nominee for the Vice Presidency for the Republican party?

Resolves Nov 7, 2028PredictIt vs Kalshi / Robinhood
Matched
YES onPredictIt
3¢
NO onKalshi / Robinhood
97¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Ro Khanna be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
3¢
NO onPredictIt
97¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Barack Obama be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Kalshi / Robinhood vs Polymarket
Matched
YES onKalshi / Robinhood
0¢
NO onPolymarket
100¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Elise Stefanik be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Kalshi / Robinhood vs Polymarket
Matched
YES onKalshi / Robinhood
0¢
NO onPolymarket
99¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Rand Paul be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Kalshi / Robinhood vs Polymarket
Matched
YES onKalshi / Robinhood
1¢
NO onPolymarket
99¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Vivek Ramaswamy be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Polymarket vs Kalshi / Robinhood
Matched
YES onPolymarket
0¢
NO onKalshi / Robinhood
100¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Ted Cruz be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Polymarket vs Kalshi / Robinhood
Matched
YES onPolymarket
1¢
NO onKalshi / Robinhood
99¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Raphael Warnock be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Kalshi / Robinhood vs Polymarket
Matched
YES onKalshi / Robinhood
0¢
NO onPolymarket
99¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Zohran Mamdani be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Kalshi / Robinhood vs Polymarket
Matched
YES onKalshi / Robinhood
0¢
NO onPolymarket
100¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Kristi Noem be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Kalshi / Robinhood vs Polymarket
Matched
YES onKalshi / Robinhood
0¢
NO onPolymarket
100¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will John Fetterman be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Kalshi / Robinhood vs Polymarket
Matched
YES onKalshi / Robinhood
0¢
NO onPolymarket
100¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Gina Raimondo be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Kalshi / Robinhood vs Polymarket
Matched
YES onKalshi / Robinhood
0¢
NO onPolymarket
100¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Pete Buttigieg be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028PredictIt vs Kalshi / Robinhood
Matched
YES onPredictIt
5¢
NO onKalshi / Robinhood
95¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Mark Cuban be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Polymarket vs Kalshi / Robinhood
Matched
YES onPolymarket
1¢
NO onKalshi / Robinhood
99¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Mike Pence be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Kalshi / Robinhood vs Polymarket
Matched
YES onKalshi / Robinhood
0¢
NO onPolymarket
100¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Jared Polis be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Kalshi / Robinhood vs Polymarket
Matched
YES onKalshi / Robinhood
0¢
NO onPolymarket
100¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Matt Gaetz be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Kalshi / Robinhood vs Polymarket
Matched
YES onKalshi / Robinhood
0¢
NO onPolymarket
100¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Hunter Biden be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Kalshi / Robinhood vs Polymarket
Matched
YES onKalshi / Robinhood
0¢
NO onPolymarket
100¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Bernie Sanders be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Kalshi / Robinhood vs Polymarket
Matched
YES onKalshi / Robinhood
1¢
NO onPolymarket
99¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Marjorie Taylor Greene be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
1¢
NO onPredictIt
99¢
Combined cost: 100¢ (over $1, no lock right now)

Who will leave Trump's Cabinet next? Will Pete Hegseth be the next person to leave the Trump Cabinet?

Resolves Jan 20, 2029PredictIt vs Kalshi / Robinhood
Matched
YES onPredictIt
12¢
NO onKalshi / Robinhood
88¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Chris Murphy be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Polymarket vs Kalshi / Robinhood
Matched
YES onPolymarket
1¢
NO onKalshi / Robinhood
99¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Andrew Yang be the nominee for the Presidency for the Democratic party?

Resolves Nov 7, 2028Polymarket vs Kalshi / Robinhood
Matched
YES onPolymarket
0¢
NO onKalshi / Robinhood
100¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Michelle Obama be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Polymarket vs Kalshi / Robinhood
Matched
YES onPolymarket
1¢
NO onKalshi / Robinhood
99¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Erika Kirk be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Polymarket vs Kalshi / Robinhood
Matched
YES onPolymarket
0¢
NO onKalshi / Robinhood
100¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Steve Bannon be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Polymarket vs Kalshi / Robinhood
Matched
YES onPolymarket
0¢
NO onKalshi / Robinhood
100¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Democratic presidential nominee Will Tim Walz be the Democratic Presidential nominee in 2028?

Resolves Nov 7, 2028Polymarket vs Kalshi / Robinhood
Matched
YES onPolymarket
0¢
NO onKalshi / Robinhood
100¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Republican presidential nominee Will John Thune be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Polymarket vs Kalshi / Robinhood
Matched
YES onPolymarket
0¢
NO onKalshi / Robinhood
100¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Republican presidential nominee Will Katie Britt be the nominee for the Presidency for the Republican party?

Resolves Nov 7, 2028Kalshi / Robinhood vs Polymarket
Matched
YES onKalshi / Robinhood
0¢
NO onPolymarket
100¢
Combined cost: 100¢ (over $1, no lock right now)

2028 Republican VP nominee Will Ron DeSantis be the nominee for the Vice Presidency for the Republican party?

Resolves Nov 7, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
3¢
NO onPredictIt
98¢
Combined cost: 101¢ (over $1, no lock right now)

2028 Republican VP nominee Will Glenn Youngkin be the nominee for the Vice Presidency for the Republican party?

Resolves Nov 7, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
4¢
NO onPredictIt
97¢
Combined cost: 101¢ (over $1, no lock right now)

2028 Republican VP nominee Will Tulsi Gabbard be the nominee for the Vice Presidency for the Republican party?

Resolves Nov 7, 2028PredictIt vs Kalshi / Robinhood
Matched
YES onPredictIt
2¢
NO onKalshi / Robinhood
99¢
Combined cost: 101¢ (over $1, no lock right now)

Who will leave Trump's Cabinet next? Will Kelly Loeffler be the next person to leave the Trump Cabinet?

Resolves Jan 20, 2029Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
3¢
NO onPredictIt
98¢
Combined cost: 101¢ (over $1, no lock right now)

Who will leave Trump's Cabinet next? Will Sean Duffy be the next person to leave the Trump Cabinet?

Resolves Jan 20, 2029Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
3¢
NO onPredictIt
98¢
Combined cost: 101¢ (over $1, no lock right now)

Who will leave Trump's Cabinet next? Will Doug Collins be the next person to leave the Trump Cabinet?

Resolves Jan 20, 2029Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
3¢
NO onPredictIt
98¢
Combined cost: 101¢ (over $1, no lock right now)

2028 Democratic VP nominee Will Pete Buttigieg be the nominee for the Vice Presidency for the Democratic party?

Resolves Nov 7, 2028PredictIt vs Kalshi / Robinhood
Matched
YES onPredictIt
8¢
NO onKalshi / Robinhood
93¢
Combined cost: 101¢ (over $1, no lock right now)

2028 Democratic VP nominee Will Wes Moore be the nominee for the Vice Presidency for the Democratic party?

Resolves Nov 7, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
4¢
NO onPredictIt
97¢
Combined cost: 101¢ (over $1, no lock right now)

Both markets are about Wes Moore winning the 2028 Democratic vice presidential nomination.

2028 Democratic Presidential ticket Will Gavin Newsom and Gretchen Whitmer be the 2028 Democratic Presidential ticket?

Resolves Nov 14, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
4¢
NO onPredictIt
98¢
Combined cost: 102¢ (over $1, no lock right now)

2028 Democratic VP nominee Will Gretchen Whitmer be the nominee for the Vice Presidency for the Democratic party?

Resolves Nov 7, 2028PredictIt vs Kalshi / Robinhood
Arb 21d ago
YES onPredictIt
12¢
NO onKalshi / Robinhood
91¢
Combined cost: 102¢ (over $1, no lock right now)

Both markets ask whether Gretchen Whitmer will win the 2028 Democratic vice presidential nomination.

Who will leave Trump's Cabinet next? Will Chris Wright be the next person to leave the Trump Cabinet?

Resolves Jan 20, 2029Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
5¢
NO onPredictIt
98¢
Combined cost: 103¢ (over $1, no lock right now)

Who will leave Trump's Cabinet next? Will Lee Zeldin be the next person to leave the Trump Cabinet?

Resolves Jan 20, 2029Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
5¢
NO onPredictIt
98¢
Combined cost: 103¢ (over $1, no lock right now)

Who will leave Trump's Cabinet next? Will Jamieson Greer be the next person to leave the Trump Cabinet?

Resolves Jan 20, 2029Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
5¢
NO onPredictIt
98¢
Combined cost: 103¢ (over $1, no lock right now)

Who will be the next Supreme Court justice? Will Andrew Oldham become the next Justice on the Supreme Court?

Resolves Feb 3, 2029Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
21¢
NO onPredictIt
82¢
Combined cost: 103¢ (over $1, no lock right now)

2028 Democratic VP nominee Will Andy Beshear be the nominee for the Vice Presidency for the Democratic party?

Resolves Nov 7, 2028PredictIt vs Kalshi / Robinhood
Matched
YES onPredictIt
9¢
NO onKalshi / Robinhood
94¢
Combined cost: 103¢ (over $1, no lock right now)

Both markets are about Andy Beshear winning the 2028 Democratic vice presidential nomination.

2028 Democratic VP nominee Will Alexandria Ocasio-Cortez be the nominee for the Vice Presidency for the Democratic party?

Resolves Nov 7, 2028Kalshi / Robinhood vs PredictIt
Arb 2d ago
YES onKalshi / Robinhood
8¢
NO onPredictIt
95¢
Combined cost: 103¢ (over $1, no lock right now)

French presidential election: who will advance? Will Bernard Cazeneuve qualify for the runoff in the 2027 French presidential election?

Resolves Apr 17, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
6¢
NO onPredictIt
98¢
Combined cost: 104¢ (over $1, no lock right now)

French presidential election: who will advance? Will Sébastien Lecornu qualify for the runoff in the 2027 French presidential election?

Resolves Apr 17, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
6¢
NO onPredictIt
98¢
Combined cost: 104¢ (over $1, no lock right now)

Who will leave Trump's Cabinet next? Will Brooke Rollins be the next person to leave the Trump Cabinet?

Resolves Jan 20, 2029Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
7¢
NO onPredictIt
98¢
Combined cost: 105¢ (over $1, no lock right now)

Who will leave Trump's Cabinet next? Will John Ratcliffe be the next person to leave the Trump Cabinet?

Resolves Jan 20, 2029Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
7¢
NO onPredictIt
98¢
Combined cost: 105¢ (over $1, no lock right now)

Who will leave Trump's Cabinet next? Will Markwayne Mullin be the next person to leave the Trump Cabinet?

Resolves Jan 20, 2029Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
11¢
NO onPredictIt
99¢
Combined cost: 110¢ (over $1, no lock right now)

French presidential election: who will advance? Will Jean-Luc Mélenchon qualify for the runoff in the 2027 French presidential election?

Resolves Apr 17, 2028PredictIt vs Kalshi / Robinhood
Matched
YES onPredictIt
40¢
NO onKalshi / Robinhood
74¢
Combined cost: 114¢ (over $1, no lock right now)

French presidential election: who will advance? Will Gabriel Attal qualify for the runoff in the 2027 French presidential election?

Resolves Apr 17, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
18¢
NO onPredictIt
99¢
Combined cost: 117¢ (over $1, no lock right now)

Who will leave Trump's Cabinet next? Will Robert F. Kennedy Jr. be the next person to leave the Trump Cabinet?

Resolves Jan 20, 2029Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
34¢
NO onPredictIt
95¢
Combined cost: 129¢ (over $1, no lock right now)

French presidential election: who will advance? Will Édouard Philippe qualify for the runoff in the 2027 French presidential election?

Resolves Apr 17, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
44¢
NO onPredictIt
96¢
Combined cost: 140¢ (over $1, no lock right now)

How we find it

We pull open binary markets from every venue, normalize each to a single YES/NO price (the cost of a $1 payout), and match the same real-world event across venues. An agent confirms both legs resolve on identical criteria before a pair lists, then we refresh prices every 30 minutes and flag the moments a combined cost drops under $1.

Why we do not trade it for you

Real execution carries risk we are not taking on: payout timing differs across venues, capital is locked until resolution, and fees, gas, KYC and withdrawal limits eat into the spread. Live arbs are often fleeting. This is a structured feed, not financial advice. Verify the resolution criteria and fees yourself before trading.

Prediction market arbitrage API and MCP for agents

Every match on this board is also a free JSON API and an MCP tool, so a trading agent can poll live Polymarket, Kalshi and PredictIt arbitrage opportunities and act on them. No API key required.

API reference →Live JSON endpoint →MCP get_arbitrage tool →
curl https://www.startuphub.ai/api/v1/arbitrage?arbs_only=1

Prediction market arbitrage, explained

What is prediction market arbitrage?
When the same event trades on more than one venue (Polymarket, Kalshi/Robinhood, PredictIt), the YES price on one venue and the NO price on another can add up to less than $1. Buying both locks a guaranteed $1 payout for less than $1, and the difference is the arbitrage.
Is there a Polymarket vs Kalshi arbitrage API?
Yes. This board is a free JSON API at /api/v1/arbitrage and an MCP tool (get_arbitrage), so bots and agents can poll live Polymarket, Kalshi and PredictIt arbitrage opportunities without scraping each venue.
Which venues are covered?
Polymarket, Kalshi (and Robinhood, which trades on Kalshi's exchange), and PredictIt. Every market is normalized to a single YES/NO price and matched to the same real-world event across venues.
Is it free, and is this financial advice?
The board and the API are free, no signup. This is an informational feed, not financial advice. Live arbitrages are often fleeting, and fees, KYC, gas and withdrawal limits eat into the spread, so verify each market's resolution rules and costs before trading.