UFC 330: Charles Johnson vs. Eduardo Chapolin (Catchweight, Prelims)

Platform comparison

Market context

Charles Johnson faces Eduardo Chapolin in a catchweight preliminary bout at UFC 330, headlined by Islam Makhachev versus Garry Machado, on 15 August 2026. The market currently reflects 100% implied probability for Johnson, suggesting near-certainty among traders. This extreme skew is unusual for a preliminary fight between fighters without dominant public profiles, and warrants scrutiny against available sportsbook pricing and fight-week developments.

Preliminary bouts in major UFC cards historically show wider probability distributions than main-card fights, particularly when one fighter carries recent momentum or a notable win streak. Johnson's current 100% implied probability suggests either substantial recent form divergence—a knockout streak, injury to Chapolin, or significant public information asymmetry—or potential liquidity constraints in this specific market. Cross-platform comparison with major sportsbooks (DraftKings, FanDuel, BetMGM) would reveal whether this consensus reflects genuine edge or market thinness. Preliminary fights also settle more frequently as No Contests or technical draws due to injury stoppages or weight-cut complications, which would trigger the 50-50 resolution clause.

Traders should monitor official UFC weigh-in results on 14 August and any late injury announcements, as catchweight bouts sometimes face last-minute adjustments. Fighter social media activity and training-camp updates in the week preceding the event typically signal confidence levels. The settlement window closes 16 August at 03:59:59 UTC, allowing roughly 24 hours post-fight for official UFC confirmation. Any postponement beyond 29 August automatically resolves the market 50-50, a tail risk worth pricing if preliminary-card scheduling instability emerges.

Methodology

We track UFC 330: Charles Johnson vs. Eduardo Chapolin (Catchweight, Prelims) across the five venues with material prediction-market liquidity. The probability shown is the live Polymarket mid; the comparison rows summarise how each venue treats the underlying contract — fees, KYC thresholds, settlement currency, deposit options. The highlighted row marks the cheapest route into Polymarket's order book.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

How reliable are the quoted odds?

The YES/NO percentages are the live mid-prices of the Polymarket order book. On deep markets they move every few seconds; on thinner ones you'll see short plateaus.