It is incredibly volatile. Spot prices in the day-ahead auction for tomorrow are between -39€/MWh and 201€/MWh. And that's a pretty normal amount of volatility for this time of year
Would be good to have more than a one sentence explanation of what you mean, but this is a result of low storage. In the oil market, if prices are too volatile you just stick it in a tank until they stabilize. You only get negative prices if all the storage is full, which happened to WTI once.
