ERCOT Peak Demand Prediction Markets vs. the Texas Grid

By Arthur Angelo, PredictionScout Research · Updated Oct 23, 2026, 8:32 AM ET

Key findings

• Typical miss 736 MW (average 1,030 MW) over 51 days.
• Threshold contracts right 91% of the time (578 of 635 “above X MW” contracts).
• Market vs. “same as yesterday.” On the 34 days where we have ERCOT’s previous-day peak, the market’s median miss was 740 MW against 2,274 MW for simply repeating yesterday’s peak; the market was closer on 21 of 34 days.
• Biggest miss: Sep 30. Market median 81,833 MW, actual peak 77,838 MW.
• Highest peak in our ERCOT archive: 86,168 MW on Sep 16, 2026 (hour ending 17:00 CT).
• Settlement check. 35 of 35 days with an ERCOT report on file match Kalshi’s settlement value. Kalshi sometimes shows its settlement rounded to the whole megawatt; differences under 1 MW count as a match. ERCOT keeps only about 30 days of this report online, so earlier days rely on Kalshi’s settlement value.

ERCOT daily peak load

Across 51 days from Aug 30, 2026 to Oct 22, 2026, the market’s median on the morning of the day was off by 736 MW on a typical day (median miss) and 1,030 MW on average. The number came in above the market median 23 times and below it 28 times. Of 635 individual “above X” contracts, the side priced above 50¢ that morning was right 578 times (91%).

Highlighted rows missed by more than 3,000 MW. Official values: ERCOT Actual System Load by Weather Zone (NP6-346-CD), highest hourly TOTAL for the operating day.

Download the data

Day-by-day scorecard (CSV)

One row per settled Kalshi event: the market median 14 hours before close, Kalshi’s settlement value, the official first-release value and the miss. Per-contract prices are not included. Free to reuse under CC BY 4.0 with a link back to this page.

Methodology

• Markets. Kalshi’s KXTXERCOTPEAKD series: “Will the highest hourly total system load reported for the ERCOT grid on [day] be above X MW?”, from Kalshi’s public API. Each day’s market opens at midnight Central and closes just before the next midnight, so we price it 14 hours before close (about 10 AM Central), before the afternoon peak.
• Official data. ERCOT’s Actual System Load by Weather Zone report (NP6-346-CD), the source in Kalshi’s rules: the highest hourly TOTAL for each operating day. ERCOT posts this report daily and keeps about 30 days online; PredictionScout archives each day’s peak as it is published.
• Benchmark. “Same as yesterday” uses the previous operating day’s ERCOT peak, which is known before the market’s pricing time.
• Market median. For each day we take every “above X” contract’s price 14 hours before trading closed (about 10 AM Central on the operating day) (midpoint of bid and ask from hourly candles when the spread is 10¢ or less, otherwise the last trade; looking back up to 48 hours). Prices are forced to fall as the threshold rises, and the median is the point where the implied chance crosses 50%, interpolated between neighboring thresholds. If the 50% point falls outside the listed thresholds the release is shown but not scored.
• Contracts called right. Each threshold contract counts once: right if the side priced above 50¢ on the morning of the day won. Contracts priced exactly 50¢ are skipped.
• Actual value. The value Kalshi settled on (its “expiration value”), taken from ERCOT’s report. We check it against the first-release value in ALFRED (St. Louis Fed’s archive of data as first published) and mark any difference.
• Limits. One exchange; thin trading in some older and far-out contracts; the market median is a summary of a full distribution, not a single forecast. Nothing here is investment advice. Last run: Oct 23, 2026, 8:32 AM ET.

Data sources: prices and volumes come from the public APIs of Kalshi and Polymarket, with grid data from ERCOT. All trademarks belong to their owners. PredictionScout is independent and not affiliated with any exchange. Nothing here is investment, betting, or legal advice.

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