What Changes on the Price Chart After Polymarket’s TWAP Implementation (Aug 7, 2026)

On August 7, 2026 at 00:00 UTC, Polymarket changed how its crypto Up/Down markets resolve.

This is not a small technical detail. It fundamentally changes what the “closing price” on the chart actually means.

Before vs After

Aspect	Before Aug 7	After Aug 7
Resolution method	Single price snapshot at expiry	Time-Weighted Average Price (TWAP)
5-minute markets	Last print / snapshot	30-second Chainlink TWAP
15-minute markets	Last print / snapshot	60-second Chainlink TWAP
4-hour markets	Last print / snapshot	60-second Chainlink TWAP
Easy last-second push	Yes	Much harder and more expensive

The open (price-to-beat) stays the same.

Only the closing reference changes.

What This Looks Like on a Price Chart

Old Behavior (Snapshot)

The market resolved on whatever the oracle printed at the exact second the window ended.

This meant:

A sharp spike or dump in the final 1–3 seconds could flip the outcome
The resolution price often matched a single candlestick close or last trade
Charts and CEX candles were relatively intuitive for manual traders

New Behavior (TWAP)

The resolution price is now an average over a short window ending at expiry:

5m markets → average of the last 30 seconds
15m / 4h markets → average of the last 60 seconds

Visually on a chart this has several effects:

Spikes get smoothed

A sudden 10–20 bps move in the final seconds is diluted by the rest of the averaging window.
Resolution no longer equals the last tick

The price you see at the exact close of the candle is no longer the settlement price.
Path inside the final window matters

Sustained pressure over 30–60 seconds is required to move the TWAP meaningfully. A single aggressive print is no longer enough.
Divergence appears

In recent pre-cutover samples, TWAP and the final snapshot already disagreed often enough to flip a non-trivial percentage of outcomes (roughly in the mid-single to low-double digit % range depending on the asset, with typical max differences of 6–12 bps).

Practical Consequences for Traders & Bots

Strategies that break or weaken

Pure last-second sniping / spoofing into the close
Bots that only watched the final tick or a single CEX close price
Any system that treated the resolution price as identical to a candlestick close

Strategies that become more robust

Systems that already used a short rolling average or TWAP-style fair value
Directional models that care about the broader path rather than a single print
Market makers who were previously being picked off by last-second manipulators

Chart-reading changes

You can no longer look at a standard 1-minute or 15-second candle close and assume that is the resolution price.

You must think in terms of the average price over the final 30–60 seconds.

Why Polymarket Made the Change

Single-price snapshots on short-duration markets are easy to manipulate when liquidity thins near expiry. A well-capitalized player can push the price for a fraction of a second, collect the payout, and leave everyone else with the loss.

Moving to a TWAP forces any attempt at manipulation to be sustained across the entire averaging window, which is dramatically more expensive and risky.

What Developers Should Do

Stop using a single closePrice / snapshot for resolution logic.
Switch to the official Chainlink 30s / 60s TWAP feeds (via Chainlink Data Streams or Polymarket RTDS).
Treat the TWAP as the only authoritative settlement value after Aug 7.
Keep gamma outcomePrices as a fallback, but prioritize the TWAP.
Re-evaluate any strategy that depended on final-second price action.

Summary

The price chart itself did not change.

What changed is the meaning of the closing price used for settlement.

After August 7, the last tick on the chart is no longer the truth.

The truth is the time-weighted average over the final 30 or 60 seconds.

That single shift makes last-second games much harder and forces every serious bot and trader to update both their signals and their resolution logic.

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