Polymarket TWAP Resolution: How Crypto Up/Down Markets Settle Now
From August 7, 2026, Polymarket up/down markets resolve on a 30s or 60s Chainlink TWAP. Here is the spec, the feeds, and the trading impact.
Polymarket changed the rule that decides who wins its short crypto contracts. From August 7, 2026 at 00:00 UTC, every 5 minute, 15 minute and 4 hour crypto up/down market settles on a time weighted average price computed by Chainlink. The old method read one price at expiry. The new method reads an average across a short window before expiry.
If you trade these markets by hand, the way you place a trade does not change. If you run a bot that polls a single closing price, your settlement logic is now wrong.
What Changed on August 7, 2026
| Item | Before August 7 | After August 7 |
|---|---|---|
| Resolution input | One Chainlink price at expiry | Chainlink computed TWAP |
| 5 minute markets | Final tick | 30 second average |
| 15 minute markets | Final tick | 60 second average |
| 4 hour markets | Final tick | 60 second average |
| Price to beat | Snapshot at open | TWAP at open |
| Cost to move an outcome | One large print | Sustained pressure for the whole window |
Both sides of the comparison now come from the same feed. The opening price to beat and the closing value both use TWAP, so you never compare an average against a snapshot.
Why the Old Snapshot Price Broke
The 5 minute crypto contracts launched on February 12, 2026 and pulled in around $4 billion in volume. They also had a hole in them. A market that resolves on one instant gives anyone with size and timing a cheap way to flip the result. Push a thin book a few basis points in the last seconds and the entire contract lands on the other side.
One review of these markets put trader losses tied to that behaviour at roughly $7.6 million.
Users flagged the problem and asked for average based settlement for months before Polymarket committed to the fix.
An independent look at a full day of Bitcoin 5 minute contracts found that more than one in ten would have resolved the other way if the last 30 seconds had been averaged. Flips inside the last five seconds accounted for a large share of those.
Honest directional traders paid for that. So did market makers, who widened quotes or left the short windows because a clean read on direction could still lose to a final print.
How Chainlink TWAP Feeds Power the New Settlement
The averaging windows
A TWAP is the average price of an asset across a lookback window. Chainlink went live with mainnet TWAP feeds on July 31, 2026 in two variants, 30 second and 60 second. Polymarket maps them by market length: 30 seconds for 5 minute contracts, 60 seconds for 15 minute and 4 hour contracts.
The 30 and 60 second figures describe the lookback, not how often the feed publishes. Reports can arrive more frequently than the window length.
Where the data comes from
Two paths exist for anyone who needs the numbers:
- Chainlink Data Streams gives direct mainnet access. You find the TWAP: 30s or TWAP: 60s ticker in the Data Streams catalogue, copy the feed ID, and pull signed reports. Pricing starts around $150 per month for select feeds, and credentials belong on a trusted backend, never in a browser.
- Polymarket RTDS, the platform's Real Time Data Streaming WebSocket, went live on August 4, 2026 and relays the same Chainlink computed values without Chainlink credentials. Polymarket names this the recommended production path.
Values arrive as fixed point integers scaled by 10^18. Divide by 10^18 for a decimal price. No floating point drift at settlement.
What Chainlink has not published
Polymarket's own documentation says Chainlink does not publish the custom feed's sampling boundaries, weighting, rounding, or behaviour on missing inputs. The practical advice from that page is short: do not try to recompute the TWAP yourself. Consume the signed value, set a freshness threshold, and define a fallback for report gaps.
That matters if you were planning to model the settlement price locally and trade the gap. You cannot reproduce it exactly right now.
Which Markets and Assets Are Covered
The change applies to the crypto up/down suite across the three short durations. Bitcoin and Ethereum markets carry most of the volume, with Solana, XRP, BNB, DOGE and HYPE also in scope.
Polymarket paired the rollout with $1 million in liquidity rewards spread across the affected markets through August.
What Polymarket TWAP Resolution Means for You
| Participant | Effect |
|---|---|
| Directional traders | Cleaner outcomes, fewer results that contradict the move you read |
| Snapshot bots | Broken settlement logic, needs a TWAP feed integration |
| Market makers | Less settlement flip risk, plus a share of the $1 million reward pool |
| Tail-end scalpers | The final tick edge is gone |
For manual traders
Buy Up if you expect the closing TWAP above the price to beat. Buy Down if you expect it below. The mechanics are identical. What changed is that a spike in the last four seconds no longer decides your trade, and a strong move that fades in the final 20 seconds still counts toward the average that settles the market.
For market makers
Quoting into a snapshot settlement meant carrying the risk that one print reverses an otherwise correct position. That risk shrinks with an average. Expect tighter spreads and more depth near expiry while the August reward program runs.
For bot operators
Any strategy that reads price at T and compares it to price at T minus N needs rewriting against the TWAP stream. Latency strategies that exploit stale Polymarket quotes against a faster read of the underlying still work, though the windows get narrower as makers reprice with more confidence.
Point your integration at the RTDS WebSocket, subscribe to the 30 second and 60 second topics for the assets you trade, and compare against the market's stored price to beat rather than a spot feed.
Checklist Before Your Next Up/Down Trade
- Confirm which TWAP window applies to the market length you are trading
- Read the price to beat from the market itself, not from a spot price API
- Watch the whole window, since the last minute no longer carries extra weight
- Set a staleness limit on the feed and decide what your bot does when a report is missing
- Check the reward terms if you plan to quote for a share of the $1 million pool
- Backtest against live TWAP data before you size up, because snapshot and average differ most on the days with the biggest moves
Frequently Asked Questions
Does TWAP resolution remove all manipulation risk?
No. It raises the cost. Moving a 30 second average takes sustained pressure across the whole window instead of one print, which is far more expensive than a single push and much easier to see.
Can I calculate the settlement price myself?
Not reliably. Chainlink has not released the sampling and weighting rules for these feeds, so a local calculation may drift from the signed value that settles the market.
Do longer Polymarket markets use TWAP?
The current change covers the 5 minute, 15 minute and 4 hour crypto up/down markets. Other market types keep their existing resolution sources.
Is the RTDS feed free?
RTDS relays Chainlink computed TWAP updates without Chainlink credentials. Direct Data Streams access is paid, starting near $150 per month for select feeds.
What happens to strategies built on the final seconds?
They lose their edge. A position that only wins because of a late tick now settles on the average that surrounds that tick.
Where This Leaves Short Timeframe Crypto Trading
Polymarket TWAP resolution puts these contracts closer to how professional venues settle short dated products. Direction still has to be read correctly and volatility has not gone anywhere. The part that disappeared is the edge that came from the settlement rule itself.
Start with one market. Pick a 5 minute Bitcoin contract, pull the price to beat, watch the 30 second TWAP feed alongside it for a few cycles, and see how often the average lands somewhere other than the last printed tick. Then trade it. If you run automated strategies, update your settlement logic against the RTDS stream today rather than after a losing resolution teaches you the difference.
