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2028 Republican presidential nominee Marco Rubio

Marco Rubio wins and accepts the 2028 Republican presidential nomination. Listed on both Kalshi and Polymarket; recorded continuously since Aug 9, 2026. Live.

kalshi
20.5¢
bid 0.2 · ask 0.21 · Sep 19, 6:02 AM ET
polymarket
15.3¢
bid 0.153 · ask 0.154 · Sep 19, 5:57 AM ET

Current gap between the two mids: 5.2¢. Over the last 7 days the two venues differed by 3.9% on average and 5.1% at most.

Price history, both venues (7 days)

kalshipolymarket
14.6%16.3%17.9%19.6%21.3%10:2018:1302:0610:00kalshipolymarket
Data table
time (UTC)kalshi midpolymarket mid
Sep 18 10:2020.5%16.2%
Sep 18 10:2520.5%16.2%
Sep 18 10:3020.5%16.2%
Sep 18 10:3520.5%16.2%
Sep 18 10:4020.5%16.2%
Sep 18 10:4520.5%16.2%
Sep 18 10:5020.5%16.2%
Sep 18 10:5520.5%16.2%
Sep 18 11:0520.5%16.2%
Sep 18 11:1020.5%16.2%
Sep 18 11:1520.5%16.0%
Sep 18 11:2020.5%15.8%
Sep 18 11:2520.5%15.9%
Sep 18 11:3020.5%15.9%
Sep 18 11:3520.5%15.8%
Sep 18 11:4020.5%15.8%
Sep 18 11:4520.5%15.8%
Sep 18 11:5020.5%15.8%
Sep 18 11:5520.5%15.8%
Sep 18 12:0020.5%15.8%
Sep 18 12:0520.5%15.8%
Sep 18 12:1020.5%15.8%
Sep 18 12:1520.5%15.8%
Sep 18 12:2020.5%15.8%
Sep 18 12:2520.5%15.8%
Sep 18 12:3020.5%15.8%
Sep 18 12:3520.5%15.8%
Sep 18 12:4520.5%15.8%
Sep 18 12:5020.5%15.7%
Sep 18 12:5520.5%15.7%
Sep 18 13:0020.5%15.7%
Sep 18 13:0520.5%15.4%
Sep 18 13:1020.5%15.4%
Sep 18 13:1520.5%15.3%
Sep 18 13:2520.5%15.3%
Sep 18 13:3020.5%15.3%
Sep 18 13:3520.5%
Sep 18 13:4520.5%
Sep 18 13:5020.5%
Sep 18 13:5520.5%
Sep 18 14:0020.5%
Sep 18 14:0520.5%
Sep 18 14:1020.5%
Sep 18 14:1520.5%
Sep 18 14:3520.5%
Sep 18 14:4020.5%
Sep 18 14:4520.5%
Sep 18 14:5020.5%
Sep 18 14:5520.5%
Sep 18 15:0020.5%
Sep 18 15:0520.5%
Sep 18 15:2520.5%
Sep 18 15:3020.5%
Sep 18 15:3520.5%
Sep 18 15:4020.5%
Sep 18 15:4520.5%
Sep 18 15:5020.5%
Sep 18 15:5520.5%
Sep 18 16:0020.5%
Sep 18 16:2020.5%
Sep 18 16:2520.5%
Sep 18 16:3020.5%
Sep 18 16:3520.5%
Sep 18 16:4520.5%
Sep 18 16:5020.5%
Sep 18 16:5520.5%
Sep 18 17:0020.5%
Sep 18 17:0520.5%
Sep 18 17:1020.5%
Sep 18 17:1520.5%
Sep 18 17:2020.5%
Sep 18 17:2520.5%
Sep 18 17:3020.5%
Sep 18 17:3520.5%
Sep 18 17:5020.5%
Sep 18 17:5520.5%
Sep 18 18:0020.5%
Sep 18 18:1020.5%
Sep 18 18:1520.5%
Sep 18 18:2020.5%
Sep 18 18:3520.5%
Sep 18 18:4020.5%
Sep 18 18:4520.5%
Sep 18 18:5020.5%
Sep 18 18:5520.5%
Sep 18 19:0020.5%
Sep 18 19:0520.5%
Sep 18 19:1020.5%
Sep 18 19:1520.5%
Sep 18 19:4020.5%
Sep 18 19:4520.5%
Sep 18 19:5520.5%
Sep 18 20:0020.5%
Sep 18 20:0520.5%
Sep 18 20:1020.5%
Sep 18 20:1520.5%
Sep 18 20:2020.5%
Sep 18 20:2520.5%
Sep 18 20:3020.5%
Sep 18 20:3520.5%
Sep 18 20:4020.5%
Sep 18 20:4520.5%
Sep 18 20:5020.5%
Sep 18 20:5520.5%
Sep 18 21:0020.5%
Sep 18 21:0520.5%
Sep 18 21:1020.5%
Sep 18 21:1520.5%
Sep 18 21:2020.5%
Sep 18 21:2520.5%
Sep 18 21:3020.5%
Sep 18 21:3520.5%
Sep 18 21:4020.5%
Sep 18 21:4520.5%
Sep 18 21:5020.5%
Sep 18 21:5520.5%
Sep 18 22:0020.5%
Sep 18 22:0520.5%
Sep 18 22:1020.5%
Sep 18 22:1520.5%
Sep 18 22:2020.5%
Sep 18 22:2520.5%
Sep 18 22:3520.5%
Sep 18 22:4020.5%
Sep 18 22:4520.5%
Sep 18 22:5020.5%
Sep 18 22:5520.5%
Sep 18 23:0020.5%
Sep 18 23:0520.5%
Sep 18 23:1020.5%
Sep 18 23:1520.5%
Sep 18 23:2020.5%
Sep 18 23:3020.5%
Sep 18 23:3520.5%
Sep 18 23:4020.5%
Sep 18 23:5020.5%
Sep 18 23:5520.5%
Sep 19 00:0020.5%
Sep 19 00:0520.5%
Sep 19 00:1020.5%
Sep 19 00:1520.5%
Sep 19 00:2020.5%
Sep 19 00:2520.5%
Sep 19 00:3520.5%
Sep 19 00:4020.5%
Sep 19 00:5020.5%
Sep 19 00:5520.5%
Sep 19 01:0020.5%
Sep 19 01:1520.5%
Sep 19 01:2020.5%
Sep 19 01:2520.5%
Sep 19 01:4020.5%
Sep 19 01:4520.5%
Sep 19 01:5020.5%
Sep 19 01:5520.5%
Sep 19 02:0520.5%
Sep 19 02:1020.5%
Sep 19 02:2520.5%
Sep 19 02:3020.5%
Sep 19 02:3520.5%
Sep 19 02:4020.5%
Sep 19 02:4520.5%
Sep 19 02:5020.5%
Sep 19 02:5520.5%
Sep 19 03:0020.5%
Sep 19 03:0520.5%
Sep 19 03:1520.5%
Sep 19 03:2020.5%
Sep 19 03:3020.5%
Sep 19 03:3520.5%
Sep 19 04:0020.5%
Sep 19 04:1020.5%
Sep 19 04:4520.5%
Sep 19 04:5020.5%
Sep 19 04:5520.5%
Sep 19 05:0020.5%
Sep 19 05:0520.5%
Sep 19 05:1020.5%
Sep 19 05:1520.5%
Sep 19 05:2020.5%
Sep 19 05:2520.5%
Sep 19 05:3020.5%
Sep 19 05:5020.5%
Sep 19 05:5520.5%
Sep 19 06:0020.5%
Sep 19 06:1520.5%
Sep 19 06:2020.5%
Sep 19 06:2520.5%
Sep 19 06:3020.5%
Sep 19 06:3520.5%
Sep 19 06:4020.5%
Sep 19 06:4520.5%
Sep 19 06:5020.5%
Sep 19 06:5520.5%
Sep 19 07:0020.5%
Sep 19 07:0520.5%
Sep 19 07:1020.5%
Sep 19 07:1520.5%
Sep 19 07:2020.5%
Sep 19 07:2520.5%
Sep 19 07:3020.5%
Sep 19 07:3520.5%
Sep 19 07:4020.5%
Sep 19 07:4520.5%
Sep 19 07:5020.5%
Sep 19 08:0020.5%
Sep 19 08:0520.5%
Sep 19 08:1020.5%
Sep 19 08:2520.5%
Sep 19 08:3020.5%
Sep 19 08:5020.5%
Sep 19 08:5520.5%
Sep 19 09:0020.5%
Sep 19 09:0520.5%
Sep 19 09:1020.5%
Sep 19 09:1520.5%
Sep 19 09:2020.5%
Sep 19 09:4020.5%
Sep 19 09:5520.5%
Sep 19 10:0020.5%

Mid price of the YES side per venue, 5-minute buckets, from continuously recorded order books. Breaks mean the recorder was down or a book was empty.

Disagreement windows
20
beyond fees, at size
Largest net edge
2.67%
avg 1.05%
Typical window
637 min
longest 4097 min
Last window
Sep 19, 2026
first Aug 21, 2026

Recent disagreement windows

OpenedClosedLengthScansMax net edge
Sep 19, 12:45 AM ETSep 19, 6:02 AM ET5.3 h972.67%
Sep 17, 5:00 AM ETSep 19, 12:14 AM ET43.2 h1,0012.51%
Sep 16, 11:13 AM ETSep 17, 4:11 AM ET17.0 h2831.65%
Sep 13, 2:22 PM ETSep 16, 10:39 AM ET68.3 h1,6491.54%
Sep 13, 6:52 AM ETSep 13, 12:58 PM ET6.1 h1560.45%
Sep 11, 6:28 PM ETSep 11, 6:28 PM ET0 min10.70%
Sep 11, 5:15 PM ETSep 11, 5:16 PM ET1 min20.91%
Sep 11, 8:03 AM ETSep 11, 9:38 AM ET1.6 h260.73%
Sep 10, 11:00 AM ETSep 10, 11:48 AM ET47 min130.21%
Sep 10, 5:33 AM ETSep 10, 6:08 AM ET35 min120.43%

Related markets on both venues

Frequently asked questions

What are the current Kalshi and Polymarket odds for "2028 Republican presidential nominee Marco Rubio"?

As of the latest recorded books, Kalshi's YES mid is 20.5¢ (bid 0.2, ask 0.21) and Polymarket's is 15.3¢ (bid 0.153, ask 0.154) — a 5.2¢ gap. Prices are recorded continuously; this page refreshes every few minutes.

Has this market been an arbitrage?

Yes — 20 separate windows where buying the cheaper side on each venue cost less than $1 after both fees, first on Aug 21, 2026 and most recently Sep 19, 2026. The largest net edge was 2.67% and windows averaged 637 minutes.

Do both contracts resolve the same way?

The pair was confirmed as the same question (AI-matched · 98%). That judgment covers the headline question; resolution rules can still differ in edge cases (sources, timing, ties). Read both venues' rules before treating a gap as risk-free.

What do the fees do to the gap?

Kalshi charges takers 7% × price × (1 − price) per contract; Polymarket charges its category rate on the same curve. Near 50¢ that is roughly 1.75¢ per contract on Kalshi and 1–1.75¢ on Polymarket, so a visible gap of 3–4¢ is typically the minimum before anything is left.

← every Kalshi↔Polymarket pair · resolution criteria · taker fees · match: AI-matched · 98%. Verify both markets' rules yourself; this is data, not advice.