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.

71 matched events across venues

6 with a live arbitrage right now

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 Polymarket
Arb +7.0%
YES onKalshi / Robinhood
8¢
NO onPolymarket
85¢
Cost to lock $1: 93¢Locked profit: 7¢ per $1

Both markets are about Alexandria Ocasio-Cortez winning the 2028 Democratic vice presidential nomination.

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

Polymarket vs PredictIt
Arb +4.7%
YES onPolymarket
12¢
NO onPredictIt
84¢
Cost to lock $1: 96¢Locked profit: 4¢ per $1

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

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

Resolves Nov 7, 2028PredictIt vs Kalshi / Robinhood
Arb +4.2%
YES onPredictIt
11¢
NO onKalshi / Robinhood
85¢
Cost to lock $1: 96¢Locked profit: 4¢ per $1

Both markets are about Alexandria Ocasio-Cortez winning the 2028 Democratic presidential nomination.

2028 Democratic VP nominee Will Josh Shapiro be the nominee for the Vice Presidency for the Democratic party?

Resolves Nov 7, 2028Kalshi / Robinhood vs PredictIt
Arb +4.1%
YES onKalshi / Robinhood
4¢
NO onPredictIt
92¢
Cost to lock $1: 96¢Locked profit: 4¢ per $1

Both markets are about Josh Shapiro winning the 2028 Democratic vice presidential nomination.

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

Resolves Nov 7, 2028Polymarket vs Kalshi / Robinhood
Arb +3.1%
YES onPolymarket
2¢
NO onKalshi / Robinhood
95¢
Cost to lock $1: 97¢Locked profit: 3¢ per $1

Both markets are about Rahm Emanuel winning the 2028 Democratic presidential nomination.

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

Both markets are about Mark Kelly winning the 2028 Democratic presidential nomination.

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

Resolves Nov 7, 2028PredictIt vs Kalshi / Robinhood
Arb 2d ago
YES onPredictIt
5¢
NO onKalshi / Robinhood
92¢
Combined cost: 97¢ (over $1, no lock right now)

Both markets are about Kamala Harris winning the 2028 Democratic presidential nomination.

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

Resolves Nov 7, 2028Polymarket vs Kalshi / Robinhood
Matched
YES onPolymarket
2¢
NO onKalshi / Robinhood
96¢
Combined cost: 98¢ (over $1, no lock right now)

Both markets are about Ron DeSantis winning the 2028 Republican presidential nomination.

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
97¢
Combined cost: 99¢ (over $1, no lock right now)

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

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

Resolves Jun 1, 2028Polymarket vs PredictIt
Matched
YES onPolymarket
20¢
NO onPredictIt
79¢
Combined cost: 99¢ (over $1, no lock right now)

Both markets ask whether Gavin Newsom will win the 2028 Democratic presidential nomination.

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)

Both markets are about Brian Kemp winning the 2028 Republican presidential nomination.

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)

Both markets are about Josh Shapiro winning the 2028 Democratic presidential nomination.

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)

Both markets are about Russell Vought being the next person to leave the Trump Cabinet.

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

Resolves Nov 7, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
14¢
NO onPredictIt
85¢
Combined cost: 99¢ (over $1, no lock right now)

Both markets are about Jon Ossoff winning the 2028 Democratic presidential nomination.

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)

Both markets are about Elon Musk winning the 2028 Republican presidential nomination.

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)

Both markets are about Jon Stewart winning the 2028 Democratic presidential nomination.

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

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

Both markets are about Stephen A. Smith winning the 2028 Democratic presidential nomination.

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: 99¢ (over $1, no lock right now)

Both markets are about Roy Cooper winning the 2028 Democratic presidential nomination.

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
3¢
NO onPredictIt
97¢
Combined cost: 100¢ (over $1, no lock right now)

Both markets are about Ruben Gallego winning the 2028 Democratic vice presidential nomination.

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)

Both markets are about Elissa Slotkin winning the 2028 Democratic presidential nomination.

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
99¢
Combined cost: 100¢ (over $1, no lock right now)

Both markets are about Matt Gaetz winning the 2028 Republican presidential nomination.

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
99¢
Combined cost: 100¢ (over $1, no lock right now)

Both markets are about Jared Polis winning the 2028 Democratic presidential nomination.

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
99¢
Combined cost: 100¢ (over $1, no lock right now)

Both markets are about Gina Raimondo winning the 2028 Democratic presidential nomination.

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
99¢
Combined cost: 100¢ (over $1, no lock right now)

Both markets are about Barack Obama winning the 2028 Democratic presidential nomination.

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)

Both markets are about Tulsi Gabbard winning the 2028 Republican presidential nomination.

2028 Republican presidential nominee Will John Thune 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)

Both markets are about John Thune winning the 2028 Republican presidential nomination.

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)

Both markets are about Byron Donalds winning the 2028 Republican presidential nomination.

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
99¢
Combined cost: 100¢ (over $1, no lock right now)

Both markets are about John Fetterman winning the 2028 Democratic presidential nomination.

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)

Both markets are about Robert F. Kennedy Jr. winning the 2028 Republican presidential nomination.

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)

Both markets are about Ted Cruz winning the 2028 Republican vice presidential nomination.

2028 Democratic presidential nominee Will Cory Booker 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)

Both markets are about Cory Booker winning the 2028 Democratic presidential nomination.

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)

Both markets are about Ruben Gallego winning the 2028 Democratic presidential nomination.

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)

Both markets are about Ro Khanna winning the 2028 Democratic presidential nomination.

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
99¢
Combined cost: 100¢ (over $1, no lock right now)

Both markets are about Katie Britt winning the 2028 Republican presidential nomination.

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
99¢
Combined cost: 100¢ (over $1, no lock right now)

Both markets are about Zohran Mamdani winning the 2028 Democratic presidential nomination.

2028 Democratic presidential nominee Will Andrew Yang be the nominee for the Presidency for the Democratic 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)

Both markets are about Andrew Yang winning the 2028 Democratic presidential nomination.

2028 Republican presidential nominee Will Steve Bannon 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)

Both markets are about Steve Bannon winning the 2028 Republican presidential nomination.

2028 Democratic presidential nominee Will Chris Murphy 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)

Both markets are about Chris Murphy winning the 2028 Democratic presidential nomination.

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)

Both markets are about Rand Paul winning the 2028 Republican presidential nomination.

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
99¢
Combined cost: 100¢ (over $1, no lock right now)

Both markets are about Hunter Biden winning the 2028 Democratic presidential nomination.

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

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

Both markets are about Ted Cruz winning the 2028 Republican presidential nomination.

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)

Both markets are about Michelle Obama winning the 2028 Democratic presidential nomination.

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
1¢
NO onKalshi / Robinhood
99¢
Combined cost: 100¢ (over $1, no lock right now)

Both markets are about Josh Hawley winning the 2028 Republican presidential nomination.

2028 Democratic presidential nominee Will Mark Cuban 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)

Both markets are about Mark Cuban winning the 2028 Democratic presidential nomination.

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
1¢
NO onPolymarket
99¢
Combined cost: 100¢ (over $1, no lock right now)

Both markets are about Raphael Warnock winning the 2028 Democratic presidential nomination.

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
2¢
NO onPredictIt
98¢
Combined cost: 100¢ (over $1, no lock right now)

Both markets are about Markwayne Mullin being the next person to leave the Trump Cabinet.

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)

Both markets are about Marjorie Taylor Greene winning the 2028 Republican presidential nomination.

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)

Both markets are about Pete Buttigieg winning the 2028 Democratic presidential nomination.

2028 Democratic presidential nominee Will Bernie Sanders 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)

Both markets are about Bernie Sanders winning the 2028 Democratic presidential nomination.

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
1¢
NO onPolymarket
99¢
Combined cost: 100¢ (over $1, no lock right now)

Both markets are about Mike Pence winning the 2028 Republican presidential nomination.

2028 Republican presidential nominee Will Erika Kirk 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)

Both markets are about Erika Kirk winning the 2028 Republican presidential nomination.

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)

Both markets are about Ron DeSantis winning the 2028 Republican vice presidential nomination.

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)

Both markets are about Tulsi Gabbard winning the 2028 Republican vice presidential nomination.

2028 Democratic VP nominee Will Jon Ossoff 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 Jon Ossoff winning the 2028 Democratic vice presidential nomination.

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)

Both markets are about Glenn Youngkin winning the 2028 Republican vice presidential nomination.

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)

Both markets are about Doug Collins being the next person to leave the Trump Cabinet.

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
89¢
Combined cost: 101¢ (over $1, no lock right now)

Both markets are about Pete Hegseth being the next person to leave the Trump Cabinet.

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)

Both markets are about Sean Duffy being the next person to leave the Trump Cabinet.

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)

Both markets are about Kelly Loeffler being the next person to leave the Trump Cabinet.

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

Resolves Nov 7, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
7¢
NO onPredictIt
95¢
Combined cost: 102¢ (over $1, no lock right now)

Both markets are about Pete Buttigieg winning the 2028 Democratic vice presidential nomination.

Who will leave Trump's Cabinet next? Will Scott Bessent be the next person to leave the Trump Cabinet?

Resolves Jan 20, 2029Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
4¢
NO onPredictIt
98¢
Combined cost: 102¢ (over $1, no lock right now)

Both markets are about Scott Bessent being the next person to leave the Trump Cabinet.

2028 Republican VP nominee Will Donald J. Trump Jr. 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
99¢
Combined cost: 103¢ (over $1, no lock right now)

Both markets are about Donald J. Trump Jr. winning the 2028 Republican vice presidential nomination.

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)

Both markets are about Jamieson Greer being the next person to leave the Trump Cabinet.

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)

Both markets are about Chris Wright being the next person to leave the Trump Cabinet.

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)

Both markets are about Lee Zeldin being the next person to leave the Trump Cabinet.

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

Resolves Nov 7, 2028Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
7¢
NO onPredictIt
97¢
Combined cost: 104¢ (over $1, no lock right now)

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

Who will leave Trump's Cabinet next? Will Linda McMahon be the next person to leave the Trump Cabinet?

Resolves Jan 20, 2029Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
6¢
NO onPredictIt
99¢
Combined cost: 105¢ (over $1, no lock right now)

Both markets are about Linda McMahon being the next person to leave the Trump Cabinet.

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)

Both markets are about John Ratcliffe being the next person to leave the Trump Cabinet.

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

Resolves Nov 7, 2028Kalshi / Robinhood vs PredictIt
Arb 14d ago
YES onKalshi / Robinhood
10¢
NO onPredictIt
96¢
Combined cost: 106¢ (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 Brooke Rollins be the next person to leave the Trump Cabinet?

Resolves Jan 20, 2029Kalshi / Robinhood vs PredictIt
Matched
YES onKalshi / Robinhood
8¢
NO onPredictIt
98¢
Combined cost: 106¢ (over $1, no lock right now)

Both markets are about Brooke Rollins being the next person to leave the Trump Cabinet.

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
40¢
NO onPredictIt
95¢
Combined cost: 135¢ (over $1, no lock right now)

Both markets are about Robert F. Kennedy Jr. being the next person to leave the Trump Cabinet.

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.