On August 14, 2026, Polymarket updated settlement for all 5-minute crypto Up/Down markets.
They moved from a 30-second Chainlink TWAP lookback to a 60-second lookback.
This is not a minor oracle tweak. It changes the variable every short-horizon directional bot is trying to predict.
What Exactly Changed
| Item | Before (pre-Aug 14) | After (current) |
|---|---|---|
| 5-minute crypto settlement | 30-second Chainlink TWAP | 60-second Chainlink TWAP |
| 15-minute markets | 60-second TWAP | 60-second TWAP (unchanged) |
| 4-hour markets | 60-second TWAP | 60-second TWAP (unchanged) |
| Opening reference | Matching TWAP window | Matching 60s TWAP |
| Final settlement | Matching TWAP window | Matching 60s TWAP |
Both the price-to-beat at slot open and the final settlement price now come from the 60-second series on 5-minute markets.
Why Polymarket Did It
The goal is market integrity.
A 30-second average still left room for short, aggressive pushes near expiry. Extending the window to 60 seconds forces any attempt at manipulation to be sustained longer, making it more expensive and less reliable.
The tradeoff is deliberate:
- Stronger protection against last-second wicks
- Smoother, slower-reacting settlement price
- Slightly less responsiveness to genuine short-term moves
Direct Effects on Trading and Bots
1. Signal models trained on 30s data are now misaligned
Any system that mapped the path of the 30s TWAP into a probability of “Up” is forecasting a different process than the one that actually settles the market.
2. Momentum and path features change
A 60-second average is smoother. Features that relied on fast noise, short spikes, or rapid reversals lose power. Models need recalibration.
3. Scratch / conviction logic must be retuned
The optimal point to flatten a weak position shifts when the underlying series is less noisy. Thresholds that worked on 30s data can now cut good trades too early or hold weak ones too long.
4. Entry timing dynamics shift
Because the settlement variable moves more slowly, the value of very late entries changes. Mid-slot accumulation relative to a 60s path behaves differently than relative to a 30s path.
5. Resolution and paper-trading labels must update
Any backtest, paper loop, or live scoring path still using the 30s feed (or an old snapshot) will produce incorrect win/loss attribution.
6. Open-price pinning must use the same series
If you pin the slot-open reference from a 30s feed while settlement uses 60s, you create a systematic mismatch between the “price to beat” you think exists and the one Polymarket actually uses.
What Did Not Change
- Chainlink still computes and signs the TWAP
- Polymarket RTDS still relays both 30s and 60s topics
- The fundamental idea remains the same: forecast the official averaging process, not a last tick
- 15-minute and 4-hour markets were already on 60s
Practical Checklist for Bot Operators
- [ ] Switch primary TWAP subscription for 5m markets to the 60s feed
- [ ] Pin slot-open reference from the same 60s series
- [ ] Update resolution / scoring logic to use 60s TWAP (with gamma as authoritative fallback)
- [ ] Re-evaluate or re-train signal features on the smoother series
- [ ] Retune scratch and position-culling thresholds
- [ ] Rebuild recent paper-trading labels under 60s rules
- [ ] Add explicit logging of which TWAP window was used for every decision and resolution
Strategic Implications
Convergence / last-tick strategies
Further weakened. The settlement target is even harder to influence with a brief push.
TWAP-aligned directional engines
Still valid in principle, but only if they actually target the current 60s series. Systems that correctly made the switch keep their structural alignment. Systems that did not are now trading a phantom target.
Market makers and fair-value models
Need to price the slower-moving average. Spreads and inventory risk near expiry look different under a 60s window.
Bottom Line
The August 14 update completed the move of 5-minute crypto markets onto the same 60-second Chainlink TWAP family already used by longer short-duration markets.
For discretionary traders the change feels like slightly smoother resolution.
For automated systems it is a hard requirement: update the feed, the reference price, the model, and the scoring path.
Anything still built around the old 30-second series is no longer solving the problem Polymarket is paying out on.
Not financial advice. Always verify the live market rules and the official TWAP window in use for the specific contract you are trading.
If you have more questions, please feel free to contact me at any time: https://t.me/abrownfox001
My Polymarket Activity: https://polymarket.com/@abrownfox001?tab=activity
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