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

Platform comparison

Market context

Charles Johnson is priced at 58% on Polymarket in a contract settled on USDC via Polygon conditional tokens, so the market is leaning towards Johnson but still leaves a meaningful chance of Eduardo Chapolin or a 50-50 outcome if the bout goes unfinished or is not scored. The underlying event is a catchweight prelim at UFC 330 in Philadelphia, with the fight listed on the card after Chapolin stepped in for an injured opponent on short notice.[1][2][14]

That 58% level reads as a modest favourite rather than a strong conviction. Johnson brings the clearer UFC track record, while Chapolin is the late replacement and less proven at this level, which is the sort of setup that often keeps a price near the middle rather than drifting decisively to one side.[1][14] Comparable UFC late-notice replacement bouts tend to reflect the favourite’s experience and the newcomer’s uncertainty, especially on undercard contests where travel, weight management and short preparation can matter more than name value.[1][14]

The key catalysts are official weigh-in and bout-day updates, plus any late change to the fight order, weight allowance or medical status before the UFC’s result is posted. UFC 330 is scheduled for 15 August 2026 in Philadelphia, with the Johnson-Chapolin bout placed on the prelims, so traders should watch for card adjustments around the early prelim and prelim windows as the event progresses.[2][3][15] Any official UFC declaration of winner, no contest, draw, cancellation or postponement beyond the market’s cut-off will determine settlement rather than judges’ score chatter or third-party live coverage.[1][11]

Sources: 1 · 2 · 3 · 4 · 5

Methodology

This page is a comparison snapshot: one live quote, four reference venues with their key attributes, and a single execution path — every trade button routes to PolyGram, which mirrors the Polymarket order book directly.

Resolution & payout

At resolution the UMA oracle takes over: a proposer posts the outcome with a bond, any token holder can dispute within two hours. Without dispute the result is accepted and the smart contract distributes USDC instantly.

On Kalshi (CFTC-regulated) resolution runs through their in-house clearing engine in USD. Betfair Exchange settles after match end in the account's local currency. Manifold pays no cash — only its in-platform "mana" currency.

FAQ

Where can I trade this market with the lowest fees?

Polymarket is geo-blocked in the US/UK/EU. The easiest 0%-fee broker into the same order book is PolyGram. Kalshi charges up to 7% per trade; Betfair Exchange takes 2-5% commission on net winnings.

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.

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.