Electricity.Trade’s May 2026 analysis shows that day-ahead exchange liquidity is becoming a more important part of the SEE power market story. Several regional exchanges recorded higher traded volumes during a month of elevated price volatility and stronger cross-border sensitivity. This matters because liquidity is what turns market stress into tradable price discovery.
SEEPEX delivered one of the clearest signals. Serbian traded volumes reached 566.3 GWh, up 16.99% month on month and 13.31% year on year. That is significant because Serbia also moved into net imports of 422.97 GWh and saw spot prices rise to €96.63/MWh. Higher volume during a tighter domestic balance suggests that market participants are increasingly using the exchange to manage exposure rather than relying only on bilateral or internal balancing arrangements.
HUPX also strengthened, with May volume rising 6.35% month on month to 2,591.57 GWh. Italy’s IPEX volume increased 4.54% to 22,994.12 GWh, Bulgaria’s IBEX rose 3.51% to 2,675.87 GWh, and Greece’s HENEX edged up 1.60% to 3,878.31 GWh. These markets all played different regional roles, but the common feature was that exchange activity increased during a period of meaningful price and flow movement.
The exceptions were Romania and Croatia. OPCOM volume fell 2.48% to 1,111.15 GWh, while CROPEX declined 3.97% to 877.24 GWh. Both markets still saw prices rise sharply, with Romania at €109.56/MWh and Croatia at €103.58/MWh. This suggests that liquidity development remains uneven across the region. Price risk is rising broadly, but the depth and responsiveness of exchange trading differ from market to market.
For traders, liquidity is not a technical detail. It affects hedging efficiency, price reliability, bid-ask behaviour, volatility management and the ability to structure PPAs or supply contracts against transparent benchmarks. As SEE markets become more exposed to renewables, imports and gas-linked marginal pricing, exchange liquidity becomes a form of market infrastructure.
Electricity.Trade should frame May as a month in which volatility and liquidity increasingly moved together, but not evenly. Serbia, Hungary, Italy, Bulgaria and Greece showed stronger day-ahead activity, while Romania and Croatia highlighted the continuing gaps. The deeper trend is that SEE power markets are becoming more tradable, but still fragmented. That fragmentation creates both risk and opportunity for utilities, traders, industrial buyers and financial counterparties.
