Inside information – often also called urgent market message (UMM) – is precise information that is not publicly known and which, if it became publicly known, would probably have a significant impact on prices on the energy market. Further explanations are available on the ACER website.
The REMIT Regulation does not define any thresholds here. Market participants must therefore decide for themselves in each case whether the information is inside information. Tip: If in doubt, disclose information.
Source: https://acer.europa.eu/en/remit/MARKET_PARTICIPANTS/Inside_information
Here you can get even more information: Q&A Inside Information with Sebastian Wykowski – YouTube