By early 2026, South-East Europe’s electricity market is increasingly shaped by where liquidity concentrates, how effectively it moves across borders, and how far intraday trading absorbs volatility. Power exchanges in the region function as price transmission engines, with depth, coupling status and participant mix affecting what industry pays per megawatt-hour.
Liquidity hierarchy among SEE power exchanges
A liquidity hierarchy is visible across the main trading platforms. HUPX, OPCOM and IBEX sit at the top, with volumes large enough to reduce single-asset dominance and support statistically reliable reference prices. SEEPEX and CROPEX form a middle tier that acts as a regional anchor while remaining sensitive to cross-border congestion.
ALPEX and BELEN are positioned on the developing edge, with their role tied more to transparency and institutional discipline than to raw liquidity. The relative depth of these venues influences how price signals travel between systems and how intraday volatility is absorbed.
Hungary, Romania and Bulgaria: high-volume reference points
Hungary’s HUPX is described as an integration bridge for the region. Daily traded day-ahead volumes operate in the 70–80 GWh range, while intraday trading is measured in terawatt-hours per month as a baseline level. The scale is linked to lower embedded risk premiums in supply contracts when suppliers hedge through HUPX.
Romania’s OPCOM operates as a volume engine rather than a corridor market. Monthly day-ahead volumes frequently exceed 1.4–1.6 TWh, supported by a generation mix spanning nuclear baseload, hydro flexibility, wind intermittency and gas marginality. Average baseload prices around €115–125/MWh in late 2025 and early 2026 are cited as reflecting a functioning market clearing mechanism.
Bulgaria’s IBEX is described as the export hub of SEE. Monthly day-ahead volumes are around 2.2–2.4 TWh, alongside record intraday volumes above 600 GWh per month. The exchange has more than 150 licensed traders alongside generators, consumers and network operators.
Western Balkans hubs: Serbia and Croatia
Serbia’s SEEPEX has annual traded volumes above 5.4 TWh and daily averages approaching 16 GWh. It is described as having moved from symbolic exchange activity to functional market operation. Over 40 active participants from more than 15 countries are cited as changing pricing behaviour toward volatility “with depth” rather than single-bid jumps.
For Serbian industry, supplier risk premiums are estimated at €4–7/MWh lower than pre-2024 bilateral-only procurement structures. Croatia’s CROPEX shows a hydro-driven profile with monthly day-ahead volumes around 0.8–0.9 TWh.
CROPEX also records meaningful intraday trading, including 15-minute products exceeding 50 GWh per month. Intraday liquidity is cited as reducing imbalance costs because thin intraday volumes lead suppliers to embed balancing risk into fixed margins.
Slovenia’s integration via ADEX and Greece’s constraint sensitivity
Slovenia’s BSP SouthPool has daily traded volumes of about 30–40 GWh, but its role is described as amplified through integration into ADEX. BSP’s participation in ADEX together with HUPX and SEEPEX is presented as lowering friction across multiple zones. The effect is that traders can arbitrage Hungary, Slovenia and Serbia within a single optimisation space.
This structure is cited as tightening spreads and accelerating price convergence during normal conditions. Greece’s power exchange ecosystem is described as large enough for daily volumes above 1.2 TWh while remaining sensitive to gas pricing, interconnector availability and renewable intermittency.
Directional congestion toward Bulgaria and Italy frequently generates spreads of €6–10/MWh, creating sustained arbitrage value. For industry, the market is described as showing that large volume does not automatically translate into low risk when cross-border constraints remain binding.
Development frontier: ALPEX and BELEN scale limits
ALPEX is described as representing potential rather than scale. Monthly volumes around 120–130 GWh and prices near €105–110/MWh indicate a functioning but still shallow market. Its importance is linked to its coupling trajectory if Albania, Kosovo, North Macedonia and Greece achieve operational coupling.
If coupling progresses, ALPEX could shift from a national transparency tool into a corridor market trading scarcity and surplus across multiple systems. Montenegro’s BELEN illustrates limits of scale with annual traded volumes below 0.35 TWh and daily averages under 1 GWh.
The exchange’s price prints are cited as swinging from €30/MWh to over €230/MWh without reflecting system-wide marginal cost. For Montenegrin industry, BELEN provides transparency but not hedging depth, leading suppliers to include high risk buffers often €10–15/MWh above regional benchmarks.
How liquidity depth affects supplier margins and delivered prices
The impact on industrial electricity prices is presented through a modeled comparison of two identical industrial buyers sourcing power in different market conditions. In markets where day-ahead liquidity exceeds 1 TWh per month and intraday liquidity exceeds 20% of day-ahead volume, supplier margins typically compress to €3–5/MWh.
Where intraday liquidity falls below 10%, margins expand toward €8–12/MWh regardless of the headline spot price level. Cross-border congestion is also cited as affecting delivered industrial prices through changes in congestion hours.
A reduction of congestion hours by 10–15% per year through improved coupling and capacity allocation typically lowers delivered industrial prices by €5–9/MWh even if average spot prices remain unchanged. The role of infrastructure and market design is therefore tied to congestion outcomes rather than isolated spot spikes.
Participant role: multi-exchange trading companies
Trading companies are described as enforcing price alignment across venues where they can operate simultaneously on multiple SEE exchanges. Firms including Axpo, MET Group, Statkraft, RWE Supply & Trading and Engie Trading are cited as operating across multiple exchanges in the region.
Their presence is linked to narrower spreads where they can trade; where they cannot trade, local monopolies are described as persisting. This participant pattern aligns with the broader liquidity hierarchy observed across exchanges.
Status by early 2026 across SEE markets
By early 2026, Romania and Bulgaria are characterized as volume engines while Hungary functions as an optimisation bridge through integration mechanisms involving HUPX and ADEX connectivity with other zones. Greece is characterized as large but constraint-sensitive in its price formation due to gas pricing drivers, interconnector availability and renewable intermittency effects.
Serbia’s SEEPEX and Croatia’s CROPEX are characterized as Western Balkans reference hubs with increasing relevance tied to deepening liquidity. Slovenia is characterized as small but structurally amplified through integration into ADEX alongside HUPX and SEEPEX.
Albania’s ALPEX and Montenegro’s BELEN are characterized as transparency markets whose future importance depends on coupling progress and scale development within the regional corridor context.
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