Values that move: corrections after first publication in European gas storage, LNG send-out and imbalance price data, 23 September to 28 October 2026

Public energy transparency data is often treated as final once it appears. We recorded every published value of five European series each time we fetched them between 23 September and 28 October 2026 and counted how many were later changed. For EU gas storage volume (GIE AGSI+), 14 of 36 gas days were corrected after first capture, all upward, by a median of 0.08 TWh and at most 2.09 TWh. For EU LNG send-out (GIE ALSI), 31 of 39 gas days were corrected, 17 of them more than once, with a median of 40 hours from first capture to last correction. For the Spanish imbalance price on the ENTSO-E Transparency Platform, 66% of surplus-price and 67% of deficit-price quarter-hours were corrected, typically about 35 hours after first capture, by up to EUR 434.70/MWh, and 142 and 140 of them changed sign. For the Austrian surplus price, 49% of quarter-hours were corrected. Each series is re-read only for a limited window after first capture, so every count is a minimum: for 21 September, 96 of 102 corrected Spanish quarter-hours had changed again by 28 October. We describe the capture, the counting rule and its limits, and publish the change records.