When the Market Moves Faster Than the Forecast — Week 39, 2026

The market averaged €162.9/MWh during Week 39, with a median of €172.0/MWh. Those central values, however, conceal a highly asymmetric week: prices climbed as high as €734.6/MWh and fell to −€5.0/MWh, producing a total weekly range of €739.6/MWh.
Tuesday, 22 September was the defining trading day. The weekly maximum of €734.6/MWh occurred at 17:45, while the largest upward interval movement, +€190.5/MWh, occurred around the same evening escalation. The subsequent reversal was equally important: the largest downward movement reached −€150.3/MWh.
Volatility was not limited to one isolated price peak. The analysis identified 68 spike intervals representing 17.0 hours, alongside 93 crash intervals representing 23.2 hours. Of these events, 34 were classified as extreme spikes and 48 as extreme crashes. The market therefore repeatedly crossed between relatively normal conditions and much more aggressive price regimes.
The distribution also shows a pronounced upper tail. The 95th-percentile threshold was €288.9/MWh, while the 99th percentile reached €496.8/MWh. The distribution had a positive skew of 1.23, confirming that the week's exceptional behaviour was weighted toward large upward price excursions even though brief negative-price conditions also occurred.
Negative prices were comparatively limited, totalling 2.2 hours, with the weekly minimum of −€5.0/MWh occurring on Sunday. The week's dominant feature was therefore not prolonged negative pricing but the speed, magnitude and recurrence of movements across the price curve.

Week 39 demonstrates why average prices alone are insufficient for understanding short-term electricity-market conditions. An average of €162.9/MWh describes the week's general price level, but it says little about the operational reality of a market capable of moving by €190.5/MWh between adjacent intervals or reaching €734.6/MWh during a concentrated evening event.
The timing of the volatility is particularly important. The heatmap identifies Tuesday as the most volatile day and around 17:00 as the most volatile hour, while Tuesday's daily spread reached €612.3/MWh. This concentration means market exposure was not evenly distributed across the week: a relatively small number of periods carried a disproportionate share of the week's price risk.
The distribution reinforces that conclusion. With a median of €172.0/MWh, a 95th-percentile threshold of €288.9/MWh and a 99th percentile of €496.8/MWh, the upper tail extended far beyond normal weekly price levels. The positive skew of 1.23 further indicates that exceptional upward movements were an important feature of the week's market structure.
For traders, flexible assets and market participants with open positions, the relevant risk was therefore both price level and ramp speed. A participant could face materially different market conditions within consecutive settlement intervals, making timing, forecasting accuracy and position management increasingly important during the identified extreme windows.

Extreme volatility creates potential value for flexibility, but Week 39 should not be interpreted as a simple high-price revenue story. The combination of sharp spikes and rapid crashes means that value depended heavily on being positioned before the movement occurred, rather than merely reacting once an extreme price became visible. The €739.6/MWh weekly range illustrates the theoretical scale of price dispersion, while Tuesday's €612.3/MWh daily spread highlights how much of that dispersion could occur within a single day. Flexible demand, storage or other dispatchable assets able to shift consumption or injection between low- and high-price periods would therefore have faced unusually wide potential operating margins. At the same time, the +€190.5/MWh rise and −€150.3/MWh fall show why volatility creates risk alongside opportunity. Incorrect timing could rapidly erode the value of an otherwise favourable market position. The platform's 60/100 High trading-risk classification captures this dual character: extreme tails created opportunity, but they also increased short-term exposure. Unlike Week 38's battery-arbitrage analysis, the supplied Week 39 analysis does not simulate realised storage revenue. A defensible revenue figure therefore cannot be assigned from these charts alone. What the data establish is the presence of unusually large and concentrated price differentials from which flexible assets could potentially extract value.

Week 39 provides a clear signal that market participants should watch not only average and peak prices, but also the frequency and concentration of extreme interval movements. The 68 extreme movements and 21.8% combined spike-and-crash event share show that significant price events occupied a meaningful portion of the reporting week.
The strongest warning signal is the concentration of risk. Tuesday ranked far above every other day in the daily volatility comparison, with Wednesday a distant second. Such clustering means weekly averages can remain relatively ordinary while individual hours become operationally and financially dominant.
For flexibility operators, the implication is to place greater emphasis on identifying high-volatility windows rather than assuming that opportunity is distributed uniformly throughout the day. For traders, the same evidence supports closer monitoring of ramp intensity and extreme-tail exposure when setting positions and risk limits.
The Week 39 evidence does not establish whether this volatility will persist into Week 40. It does, however, provide a useful benchmark: €92.6/MWh price volatility, €190.5/MWh maximum interval movement and €288.9/MWh as the upper-tail threshold are the key Week 39 reference levels against which subsequent market conditions can be assessed.