​In September 2026, quarter-hour products carried more of Germany's continuous intraday volume than hourly products for the first time. In the same month, EPEX's German order book cleared 1.35 million trades a day, 3.5x the September 2023 figure.

Both trends point to software doing more of the trading. That sharpens price formation, but it leaves behind any trader who cannot re-price at the same second-by-second speed.

The intraday continuous market is where a German battery re-optimises after the day-ahead auction, up to five minutes before delivery.

In the Modo Energy Benchmark, for a 2-hour battery trading only wholesale markets, intraday made up 15% of summer 2026 revenue, against 27% in summer 2025. The 15-minute day-ahead auction this year took most of that share from the intraday auction.

Key takeaways

• Quarter-hour products carried 50.4% of continuous volume in September 2026, up from 25% in January 2023. Day-ahead still shows an hourly sawtooth pattern, suggesting some sellers bid whole hours rather than trade quarter-hours using granular forecasts.
• Algorithmic trading bursts rose 100x, nearly all of it since XBID Release 5.0 went live on 11 June 2026. Asset owners reviewing an optimiser's backtests should ask if their systems have kept pace with the faster market.
• The top 1% of evening ID1 prices (last hour before delivery) fell from €874/MWh in summer 2024 to €539/MWh in summer 2026, even as gas prices nearly doubled. Modo Energy models the saturation of intraday price volatility based on these trends.

1. Quarter-hour products overtook hourly products in September 2026, taking most of the growth in intraday trading

In 2023 and 2024, quarter-hour volume rose each summer as solar ramps put more imbalance inside the hour, then fell back each winter. Since summer 2025, quarter-hour volume has kept climbing through the winter.

More wind and solar now put forecast error inside the hour year-round. Traders shape their positions in quarter-hours, and a growing battery fleet trades that error. The 15-minute day-ahead auction from 1 October 2025 didn’t cause a sudden shift: the trend was already underway.

2. Algorithmic trading bursts rose ~100x, stepping up with XBID Release 5.0 on 11 June 2026

EPEX's German order book stamps every trade to the second. A trader clicking fills a few trades a second, and one large order sweeping a contract's book fills dozens, all in one delivery period.

Only software re-sending a whole schedule of orders fills 100 or more trades across 10 or more delivery periods in a single second. That is what we defined here as an algorithmic burst.