A market that opens and settles inside sixty seconds has nowhere to hide a slow step. Here is what has to be true on-chain for that to work — the frozen reference tick everyone shares, odds read from the chain rather than estimated, and why the smallest on-chain stake is $2 rather than $1.
Predict Bay ·
The shortest round Predict Bay offers on Sui is one minute. A strike is fixed at the open, you take above or below, and sixty seconds later an on-chain oracle price decides it. There are also five-minute and one-hour cadences on the same rail, but the one-minute round is the interesting one, because it is the one where every piece of slowness in the design becomes visible at once.
ROUND CLOSES IN
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LAST PRICE
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STRIKE
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NO POSITIONS YET THIS ROUND — BE THE FIRST
Practice mode · no wallet, no deposit, free to start
A one-minute market has no room for a settlement path measured in minutes, a dispute window measured in hours, or a price that arrives when it arrives. It also has no room for a strike that each user computes locally, because two users disagreeing by one tick over a sixty-second horizon is not a rounding difference — it is a different bet. Most of what follows is about how those constraints get met.
Settlement latency sets the shortest round a venue can honestly offer. That is not a slogan; it is an arithmetic constraint. If confirming a transaction takes ten seconds, then a sixty-second round spends a sixth of its life in a state where the user has committed but the chain has not agreed, and the last ten seconds before expiry become unusable — you cannot accept an order you cannot confirm before the thing it is betting on has already happened.
Sui finalises in well under a second, which is what moves a sixty-second round from a race against confirmation time into an ordinary instrument. The same property is why the position lifecycle can be fully on-chain rather than matched off-chain and settled later: you mint a position, it sits in your on-chain account, and you redeem it after expiry. There is no off-chain matching engine holding the book, which DeepBook, Sui's on-chain CLOB covers in more detail.
The strike of a round is not a number the app picks. It is the reference tick — the oracle price captured on-chain when the round opens, snapped to the market's tick size, and stored on the market object itself. Every participant in that round reads the same value from the same place, because there is only one place.
It is worth being precise about why that matters more at one minute than at one hour. Over an hour, a strike computed client-side from a live feed might differ between two users by a few dollars, which is small relative to an hour of movement. Over sixty seconds it can easily be the entire range of the round. A shared, frozen, on-chain strike is what makes "above or below" a question two people can meaningfully disagree about rather than two people answering slightly different questions.
The strike itself is expressed as a price tick rather than a dollar amount, and the direction is encoded by the tick range you take. A one-sided contract uses a sentinel bound — everything above the strike, or everything below it — while a bounded pair of ticks expresses a range contract. Binary options vs prediction markets covers what that payoff shape does and does not protect you from.
The multiplier shown on the Above and Below buttons is not a local approximation. It is the protocol's own pricer, queried directly: the app asks the deployed package what a given tick range costs, for both the up range and the down range, and converts the returned probabilities into payout multipliers. The two sides sum to one, as they must for a binary.
This is done as a read-only inspection of the chain rather than a transaction, so it costs nothing, requires no signature, and works before you have signed in at all — which is why the odds are populated on the page for a logged-out visitor. The alternative most venues take is an off-chain estimator that models what the chain would say. That works until the model and the chain disagree, and the moment they do, the number on the button is not the number you get filled at. Reading the pricer removes the class of problem rather than tuning it.
The on-chain minimum is $2, where the practice rail's is lower. That is not an arbitrary product decision — it falls out of three protocol constraints interacting, and it is worth understanding because it explains the shape of the fee too.
stake / probability in quantity, and the fee is charged on quantity, the fee as a fraction of your stake grows as the contract gets longer-odds. Sizing therefore has to be fee-aware — the quantity is computed so the all-in cost lands on your stake, not so the premium alone does.Put together, a $1 ticket cannot reliably clear the premium floor once fees and lot-rounding are applied, so the interface refuses it up front rather than letting the chain abort the transaction. That is the general principle worth taking from this section: on-chain constraints are better enforced in the control than discovered in the failure.
Predict Bay runs two rails, and they are not two versions of the same thing. The practice rail is a centralised venue with simulated balances and three- or ten-minute rounds; the Sui rail is on-chain, settled in real Circle USDC, and goes down to one minute. The instrument feels identical because the question is identical — above or below a strike at expiry — but the settlement path, the funding, and what a filled order actually is all differ.
| Practice rail | Sui rail | |
|---|---|---|
| Round lengths | Three minutes, ten minutes | One minute, five minutes, one hour |
| Where the position lives | A record in Predict Bay's own system | An on-chain object in your account, minted and redeemed on Sui |
| Strike | Set by the venue at the round's open | The on-chain reference tick, readable by anyone |
| Odds | Quoted by the venue | Read from the deployed protocol's own pricer |
| Funded with | Simulated balance | Circle USDC |
| Real money | No | Yes — Sui mainnet |
The reason to run both is that they answer different objections. The practice rail is the one you can use thirty seconds after arriving, with no wallet and no funding step. The Sui rail is the one where you can verify that the strike you were given is the strike everyone was given, because it is on a public object rather than in a private database. Neither of those is a substitute for the other.