Florida Republican Governor Primary Odds: Byron Donalds at 99.0% to Win
With Florida's Republican governor primary four days away, Byron Donalds is the overwhelming favorite at 99.0% across Kalshi, Polymarket, Polymarket US, and Gemini. James Fishback is the nearest challenger at 1.1%, while Jay Collins sits at 0.3%. The market has drawn $3.2M in tracked trading volume. DeFi Rate aggregates live odds from the four exchanges and refreshes this market hourly as the August 18 primary approaches.
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Current Odds Snapshot
Current probabilities across platforms with liquidity indicators
BDByron Donalds
Vol $1.8M
Spread 0.4%
Agg
99.0%↑ +0.4%
P
99.2%
U
99.0%
K
98.8%
JFJames Fishback
Vol $1.1M
Spread 1.4%
Agg
1.1%↓ -0.4%
U
2.0%
K
1.0%
P
0.7%
JCJay Collins
Vol $229.3K
Spread 0.8%
Agg
0.3%— +0.0%
U
1.0%
K
0.3%
P
0.2%
CDCasey DeSantis
Vol $15
Spread 0.0%
Agg
0.1%— +0.0%
K
0.1%
P
0.1%
CBCharles Burkett
Vol $87
Spread —
Agg
0.1%— +0.0%
K
0.1%
JPJimmy Patronis
Vol $11
Spread 0.0%
Agg
0.1%— +0.0%
K
0.1%
P
0.1%
MGMatt Gaetz
Vol $11
Spread 0.0%
Agg
0.1%— +0.0%
K
0.1%
P
0.1%
PRPaul Renner
Vol $118
Spread —
Agg
0.1%— +0.0%
K
0.1%
WSWilton Simpson
Vol $5
Spread 0.0%
Agg
0.1%— +0.0%
K
0.1%
P
0.1%
| Outcome | Aggregated | Spread | Volume | Kalshi | Polymarket | Polymarket US | Gemini |
|---|---|---|---|---|---|---|---|
BD Byron Donalds | 99.0% ↑ +0.4% | 0.4% | $1.8M |
Kalshi
98.8%
|
Polymarket
99.2%
|
Polymarket US
99.0%
|
Gemini
—
|
JF James Fishback | 1.1% ↓ -0.4% | 1.4% | $1.1M |
Kalshi
1.0%
|
Polymarket
0.7%
|
Polymarket US
2.0%
|
Gemini
—
|
JC Jay Collins | 0.3% — +0.0% | 0.8% | $229.3K |
Kalshi
0.3%
|
Polymarket
0.2%
|
Polymarket US
1.0%
|
Gemini
—
|
CD Casey DeSantis | 0.1% — +0.0% | 0.0% | $15 |
Kalshi
0.1%
|
Polymarket
0.1%
|
Polymarket US
—
|
Gemini
—
|
CB Charles Burkett | 0.1% — +0.0% | — | $87 |
Kalshi
0.1%
|
Polymarket
—
|
Polymarket US
—
|
Gemini
—
|
JP Jimmy Patronis | 0.1% — +0.0% | 0.0% | $11 |
Kalshi
0.1%
|
Polymarket
0.1%
|
Polymarket US
—
|
Gemini
—
|
MG Matt Gaetz | 0.1% — +0.0% | 0.0% | $11 |
Kalshi
0.1%
|
Polymarket
0.1%
|
Polymarket US
—
|
Gemini
—
|
PR Paul Renner | 0.1% — +0.0% | — | $118 |
Kalshi
0.1%
|
Polymarket
—
|
Polymarket US
—
|
Gemini
—
|
WS Wilton Simpson | 0.1% — +0.0% | 0.0% | $5 |
Kalshi
0.1%
|
Polymarket
0.1%
|
Polymarket US
—
|
Gemini
—
|
Byron Donalds Probability to Win Over Time
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Tap "Chart settings" to adjust the chart.
Chart settings
Arbitrage Scanner
Current cross-venue opportunities with fee calculations
Pairs (Venue-to-Venue)
| Outcome | Venue Pair | Leg A (Buy) | Leg B (Sell) | Gross Spread | After Fees | Actionable | Trade Now |
|---|---|---|---|---|---|---|---|
JC Jay Collins |
Polymarket
→
Polymarket US | Buy @ P 0.3¢ | Sell @ U 1¢ | +0.70% | +0.70% |
No | |
JF James Fishback |
Polymarket
→
Polymarket US | Buy @ P 0.7¢ | Sell @ U 1¢ | +0.30% | +0.30% |
No | |
BD Byron Donalds |
Polymarket US
→
Polymarket | Buy @ U 99¢ | Sell @ P 99.1¢ | +0.10% | +0.10% |
No | |
CD Casey DeSantis |
Polymarket
→
Kalshi | Buy @ P 0.1¢ | Sell @ K 0¢ | -0.10% | -0.10% |
No | |
JP Jimmy Patronis |
Polymarket
→
Kalshi | Buy @ P 0.1¢ | Sell @ K 0¢ | -0.10% | -0.10% |
No | |
MG Matt Gaetz |
Polymarket
→
Kalshi | Buy @ P 0.1¢ | Sell @ K 0¢ | -0.10% | -0.10% |
No | |
WS Wilton Simpson |
Polymarket
→
Kalshi | Buy @ P 0.1¢ | Sell @ K 0¢ | -0.10% | -0.10% |
No |
Outcome Diff
| Outcome A | Outcome B | Venue | A Odds | B Odds | Diff | Strategy | Trade Now |
|---|---|---|---|---|---|---|---|
BD Byron Donalds |
CD Casey DeSantis |
Polymarket | A 99.2% | B 0.1% | +99.15% | Buy spread | |
BD Byron Donalds |
JP Jimmy Patronis |
Polymarket | A 99.2% | B 0.1% | +99.15% | Buy spread | |
BD Byron Donalds |
MG Matt Gaetz |
Polymarket | A 99.2% | B 0.1% | +99.15% | Buy spread | |
BD Byron Donalds |
WS Wilton Simpson |
Polymarket | A 99.2% | B 0.1% | +99.15% | Buy spread | |
BD Byron Donalds |
JC Jay Collins |
Polymarket | A 99.2% | B 0.2% | +99.00% | Buy spread | |
BD Byron Donalds |
CD Casey DeSantis |
Kalshi | A 98.8% | B 0.1% | +98.70% | Buy spread | |
BD Byron Donalds |
CB Charles Burkett |
Kalshi | A 98.8% | B 0.1% | +98.70% | Buy spread | |
BD Byron Donalds |
JP Jimmy Patronis |
Kalshi | A 98.8% | B 0.1% | +98.70% | Buy spread | |
BD Byron Donalds |
MG Matt Gaetz |
Kalshi | A 98.8% | B 0.1% | +98.70% | Buy spread | |
BD Byron Donalds |
PR Paul Renner |
Kalshi | A 98.8% | B 0.1% | +98.70% | Buy spread | |
BD Byron Donalds |
WS Wilton Simpson |
Kalshi | A 98.8% | B 0.1% | +98.70% | Buy spread | |
BD Byron Donalds |
JF James Fishback |
Polymarket | A 99.2% | B 0.7% | +98.55% | Buy spread | |
BD Byron Donalds |
JC Jay Collins |
Kalshi | A 98.8% | B 0.3% | +98.50% | Buy spread | |
BD Byron Donalds |
JC Jay Collins |
Polymarket US | A 99.0% | B 1.0% | +98.00% | Buy spread | |
BD Byron Donalds |
JF James Fishback |
Kalshi | A 98.8% | B 1.0% | +97.80% | Buy spread | |
BD Byron Donalds |
JF James Fishback |
Polymarket US | A 99.0% | B 2.0% | +97.00% | Buy spread | |
JF James Fishback |
JC Jay Collins |
Polymarket US | A 2.0% | B 1.0% | +1.00% | Buy spread | |
JF James Fishback |
CD Casey DeSantis |
Kalshi | A 1.0% | B 0.1% | +0.90% | Buy spread | |
JF James Fishback |
CB Charles Burkett |
Kalshi | A 1.0% | B 0.1% | +0.90% | Buy spread | |
JF James Fishback |
JP Jimmy Patronis |
Kalshi | A 1.0% | B 0.1% | +0.90% | Buy spread | |
JF James Fishback |
MG Matt Gaetz |
Kalshi | A 1.0% | B 0.1% | +0.90% | Buy spread | |
JF James Fishback |
PR Paul Renner |
Kalshi | A 1.0% | B 0.1% | +0.90% | Buy spread | |
JF James Fishback |
WS Wilton Simpson |
Kalshi | A 1.0% | B 0.1% | +0.90% | Buy spread | |
JF James Fishback |
JC Jay Collins |
Kalshi | A 1.0% | B 0.3% | +0.70% | Buy spread | |
JF James Fishback |
CD Casey DeSantis |
Polymarket | A 0.7% | B 0.1% | +0.60% | Buy spread | |
JF James Fishback |
JP Jimmy Patronis |
Polymarket | A 0.7% | B 0.1% | +0.60% | Buy spread | |
JF James Fishback |
MG Matt Gaetz |
Polymarket | A 0.7% | B 0.1% | +0.60% | Buy spread | |
JF James Fishback |
WS Wilton Simpson |
Polymarket | A 0.7% | B 0.1% | +0.60% | Buy spread | |
JF James Fishback |
JC Jay Collins |
Polymarket | A 0.7% | B 0.2% | +0.45% | Buy spread | |
JC Jay Collins |
CD Casey DeSantis |
Kalshi | A 0.3% | B 0.1% | +0.20% | Buy spread |
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
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.
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).
Polymarket US: Gateway market data (yes/no prices + best bid/ask + market stats for volume/open interest where available).
Gemini: Public Prediction Markets + ticker endpoints (best bid/ask + last + 24H USD volume when available).
Event data is updated hourly. Older history is downsampled.
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.
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.
Cheryle Shepstone
Cheryle is Director of Content and Strategy at DeFi Rate. She oversees the prediction market research, platform reviews, and editorial methodology behind every guide—from primary source verification through final fact-ch…
Florida Republicans are days away from choosing their nominee for governor, but prediction markets see little suspense left in the race.
Rep. Byron Donalds enters the August 18 primary with a commanding advantage over Lt. Gov. Jay Collins, former Florida House Speaker Paul Renner and investor James Fishback. The latest polling has reinforced that lead: Donalds is ahead by roughly 40 points in the Tampa Bay Times polling average.
The market has been there for weeks. In July, DeFiRate reported that prediction markets had Donalds at 94% on Kalshi and 96% on Polymarket, with traders already treating a Republican win in November as the more likely outcome.
The primary may be close to settled. The bigger question is whether the general election will be.
Major events and how Florida Republican primary odds moved
Listed latest first, the table tracks Byron Donalds’ Kalshi Yes price around major events in the Republican primary. Movement is measured from the last hourly price before the event’s UTC date to the final hourly price approximately 48 hours later; notable interim highs are included. The timing is descriptive and does not prove that each event caused the full move.
| Date | Major event | Kalshi Donalds Yes movement | What happened |
|---|---|---|---|
| Aug. 11, 2026 | The Tampa Bay Times polling average put Donalds roughly 40 points ahead as the primary entered its final week. | 98.5% → 98.2% (briefly 98.6%) | Near-ceiling odds barely moved. |
| Aug. 4, 2026 | Trump reiterated his complete endorsement of Donalds roughly two weeks before the primary. | 97.4% → 97.6% (briefly 97.7%) | The already-established endorsement produced only a small additional move. |
| July 27, 2026 | A Leon County judge ruled that James Fishback could remain on the Republican primary ballot after a residency challenge. | 97.0% → 96.7% (briefly 97.5%) | A rival stayed on the ballot, but Donalds remained the overwhelming favorite. |
| July 24, 2026 | Ken Griffin contributed $10 million to support Donalds, pushing reported campaign fundraising above $100 million. | 97.7% → 97.2% (briefly 97.8%) | The funding news produced no sustained increase at already elevated odds. |
| July 3, 2026 | Agriculture Commissioner Wilton Simpson endorsed Donalds, completing his sweep of endorsements from Florida’s three elected Cabinet officials. | 95.5% → 95.7% (briefly 96.0%) | The institutional consolidation produced a modest increase. |
| June 12, 2026 | Qualifying closed with Donalds, Jay Collins, James Fishback and Paul Renner on the Republican ballot; the state party’s planned debate was canceled because only Donalds met all participation thresholds. | 92.4% → 93.2% (briefly 94.5%) | Final qualification and the debate decision coincided with a short-term increase. |
| April 2, 2026 | An Emerson College poll showed Donalds dominating the GOP field, one day after his campaign reported a record $22.2 million quarter. | 84.0% → 90.0% | The strongest sustained increase among the selected 2026 events. |
| Feb. 27, 2026 | A new poll gave Donalds a 40-point primary lead as nine Republican state senators endorsed him. | 77.0% → 75.0% (briefly 81.0%) | An initial increase faded within 48 hours. |
| Jan. 12, 2026 | Lt. Gov. Jay Collins entered the Republican primary, adding a statewide officeholder with ties to the DeSantis administration. | 80.0% → 78.0% (briefly 81.0%) | Donalds’ odds declined modestly as another prominent challenger joined. |
| Dec. 18, 2025 | Donalds’ campaign reported raising more than $40 million while highlighting a wide polling lead. | 78.0% → 75.0% (briefly 79.0%) | The fundraising milestone produced little sustained movement. |
| Nov. 24, 2025 | Investment-firm founder James Fishback entered the Republican primary. | 76.0% → 68.0% (briefly 77.0%) | Donalds’ price fell over the next 48 hours as the field widened, although timing alone does not establish causation. |
| Sept. 3, 2025 | Former Florida House Speaker Paul Renner entered the Republican race against Trump-backed Donalds. | 59.0% → 57.0% (briefly 66.0%) | A brief rise faded as the field expanded. |
| Feb. 25, 2025 | Donalds formally announced his campaign for Florida governor. | 65.0% → 76.0% (briefly 77.0%) | Odds recovered after the launch, extending the repricing that followed Trump’s support. |
| Feb. 20, 2025 | President Donald Trump backed Donalds for the 2026 Florida governor race before Donalds formally entered. | 51.0% → 77.0% (briefly 86.0%) | The endorsement produced the largest repricing in the selected timeline. |
The overall pattern is clear: Trump’s early endorsement produced the decisive repricing, while later polling, fundraising and ballot developments caused much smaller moves. By the final weeks of the primary, Donalds was already trading near 98%, leaving little room for additional upside.
Donalds has taken the suspense out of the Republican primary
Donalds has President Donald Trump’s endorsement, the biggest financial operation in the race and a polling lead none of his Republican rivals has managed to dent.
The Tampa Bay Times polling average puts his advantage at about 40 points heading into the final week. A separate recent poll had Donalds leading the Republican field by 31 points, while David Jolly held a narrower seven-point advantage in the Democratic primary.
Donalds has also consolidated support beyond Trump’s orbit. Several prominent allies of outgoing Gov. Ron DeSantis have broken with the governor and endorsed Donalds, even as DeSantis himself has declined to endorse him.
The combination of polling, endorsements and money leaves traders with little reason so far to price a late Republican upset.
The Florida governor race gets more interesting in November
The general election is not as settled as the Republican primary.
Former Republican congressman David Jolly is the Democratic frontrunner and has made his political crossover part of his case for making Florida competitive again. Jolly left the Republican Party, became an independent and eventually joined the Democrats.
Recent polling gives him an argument. A July University of North Florida survey had Donalds ahead 46% to 41%, while another August poll put Donalds ahead 45% to 38% among likely voters.
The financial picture is much less competitive.
Donalds and the groups supporting him have raised more than $100 million, compared with roughly $10 million for Jolly, according to an Associated Press examination of the race.
Jolly is also running against Florida’s recent history. Donald Trump carried the state in three consecutive presidential elections, and DeSantis won reelection by nearly 20 points in 2022.
That leaves a clear split between the polls and the political backdrop. Some head-to-head polling suggests Jolly can keep the race within single digits. Florida’s recent voting record, fundraising and prediction-market prices continue to favor Republicans.
What is shaping Florida governor odds right now?
- Donalds’ polling lead: The Republican primary has moved beyond a conventional frontrunner race. Donalds is ahead by roughly 40 points in the Tampa Bay Times polling average with the August 18 vote approaching.
- Trump’s endorsement: Trump backed Donalds early, giving him a clear lane in a Republican electorate that has repeatedly sided with the president. DeSantis has stayed out of the endorsement fight, while some of his own allies have moved to Donalds.
- The money gap: Donalds and his allies have raised more than $100 million. Jolly is at roughly one-tenth of that total. If they become the nominees, Donalds enters the general election able to spend heavily from the start.
- Jolly’s head-to-head polling: The Democratic case for a competitive race rests partly on surveys showing Jolly closer to Donalds than Florida’s recent statewide results might suggest. One July poll had the gap at five points.
- Florida’s shift to the right: Republicans are no longer treating Florida like the perennial swing state it was a decade ago. Trump has won it three times, DeSantis won his second term in a landslide and Republicans have built a substantial voter-registration advantage.
The August 18 results will give traders the next hard data point. Assuming Donalds and Jolly advance, attention should move quickly to their margins, turnout and the first wave of post-primary head-to-head polling.
How trading on the Florida governor election works
Prediction markets let you trade on an election outcome through contracts that settle at $1 if the outcome happens and $0 if it does not.
Take Donalds winning the Republican nomination. If a YES contract is trading at 95¢, the market is effectively assigning him about a 95% probability of winning.
Buying 100 YES contracts at 95¢ would cost $95 before fees. If Donalds wins the nomination and the market resolves YES, the contracts settle for $100, producing a $5 profit. If he loses, they settle at $0.
You can also sell before the election.
Suppose you bought Donalds at 80¢ earlier in the campaign and his price subsequently climbed to 95¢ as his polling lead widened. You could sell the position rather than wait for the primary to resolve. The 15-cent move represents the change in what traders were willing to pay for the same outcome.
That is why the market can be useful even if you never place a trade. It creates a continuously changing probability that reacts to polls, endorsements, fundraising, debates and election results rather than waiting for a new forecast to be published.
Where to trade Florida governor prediction markets
Election markets are available across several US prediction exchanges. Prices, liquidity, fees and available contracts can differ, so it is worth comparing platforms before trading.
Kalshi: One of the largest US prediction exchanges and a major source of political market liquidity. Kalshi operates its own CFTC-regulated Designated Contract Market and lists contracts across elections, economics, sports and current events. New users can currently qualify for Trade $10, Get $15 using promo code RATE, subject to the offer’s terms and eligibility. See the Kalshi offer for current details.
Polymarket: Politics has long been one of Polymarket’s strongest categories, making it useful for following the Florida race alongside congressional control, other governor races and national political markets. Polymarket US has also expanded its regulated political-market offering in 2026. New users can currently qualify for Deposit $10, Get $20 Trading Bonus using promo code RATE. See the Polymarket offer for eligibility and terms.
Gemini Predictions: Gemini brings event contracts into the same ecosystem as its established crypto exchange, with political, economic and sports markets available through its CFTC-regulated prediction business. It is a newer market than Kalshi and Polymarket, making liquidity and pricing particularly worth comparing before trading. New users can currently qualify for Trade $10, Get $10 using promo code RATE. See the Gemini offer for current details and terms.
Florida residents can also compare other exchanges and state-specific availability in our Florida prediction markets guide.
FAQ
Byron Donalds is the overwhelming favorite heading into the August 18 primary. His advantage is supported by both prediction-market pricing and polling, with the Tampa Bay Times polling average putting him roughly 40 points ahead.
Byron Donalds leads the Republican field, while former Rep. David Jolly is the Democratic frontrunner. If both win their August 18 primaries, the two are expected to meet in the November 3 general election.
Recent polls suggest the race could be closer than Florida’s recent statewide election results. A July UNF poll had Donalds ahead 46% to 41%, while a more recent survey had him ahead 45% to 38% among likely voters. Donalds nevertheless has a substantial fundraising advantage and is running in a state that has moved toward Republicans.
The Republican and Democratic primaries are August 18, 2026.
Florida will elect its next governor on November 3, 2026. The winner will succeed term-limited Gov. Ron DeSantis.