South-East Europe’s power market is often described through exchanges and interconnectors, but the day-to-day reality is that liquidity is delivered by trading houses. They determine whether price spreads close quickly or persist for hours, whether intraday volatility becomes an opportunity or a penalty, and whether industrial buyers are offered tight index-based supply or contracts loaded with risk premiums. Expanding the previous framework, the next logical layer is to map influence by trader type and corridor, then quantify how trader density changes delivered industrial electricity prices over a year.
The region is now shaped by three archetypes of traders. The first archetype is the multi-hub optimisation trader, typified by GEN-I, which is built around speed, access and corridor management rather than generation ownership. The second archetype is the generation-anchored portfolio trader, typified by EFT, which monetises physical control and export optionality from resource-rich but liquidity-thin systems. The third archetype is the utility-trading complex, represented by national champions and their trading arms such as PPC, MVM, CEZ, and the trading desks embedded in large producers like Slovenia’s HSE, Croatia’s HEP, and parts of the Romanian and Bulgarian utility ecosystem.
GEN-I’s influence map starts with geography. Slovenia is a small system, but it sits at a structural crossroads where Austrian, Italian, Hungarian and Croatian price signals collide. That location makes Slovenian trading desks uniquely capable of acting as relay stations: they see four market curves at once and can reposition portfolios continuously. GEN-I’s core influence therefore concentrates on corridors where market coupling and access are strong enough for rapid convergence, particularly the Slovenia–Italy and Slovenia–Austria interfaces, and the linkages into Hungary and Croatia. In practical terms, GEN-I’s behaviour compresses the duration of price dislocations, because it reacts quickly when spreads open and has the market access to clear them before slower participants arrive. In winter 2026 conditions, this is especially valuable because many price spikes in SEE are not structural scarcity events but short-lived forecast deviations: wind underperformance, hydro inflow surprises, or demand ramps that were mis-estimated in day-ahead scheduling. A trader that can reposition in the intraday window does not merely profit; it stabilises the reference curve that suppliers use when pricing industrial contracts.
EFT’s influence map is structurally different. EFT’s comparative advantage arises from physical optionality across Western Balkan generation assets and export corridors, particularly those tied to Bosnia and Herzegovina, Serbia, Montenegro and, indirectly, Croatia and Italy. In corridors where market liquidity is thin and local systems can swing between surplus and deficit, a generation-anchored trader often becomes the marginal volume setter. That means EFT’s dispatch decisions and export routing can influence not only traded volumes but also the distribution of scarcity across neighbouring zones. This does not require market power in a legal sense; it emerges naturally when a small number of players control flexible physical output in a thin marketplace. In Montenegro-like conditions, where exchange liquidity is shallow and import dependence can spike, a trader with access to exportable generation can act as an effective price gatekeeper, particularly in peak hours when cross-border capacity binds and local bids thin out.
The utility-trading archetype provides the region’s inertia and baseline. These entities do not always arbitrage aggressively, but they carry large obligations and portfolios that keep markets supplied. Their trading arms tend to be most influential in their domestic zones and on adjacent borders. Greece’s PPC trading logic, for example, is shaped by a system that is still highly sensitive to gas marginal pricing and interconnector constraints. Hungary’s MVM Partner operates in a market that is deeply coupled and therefore uses hub optimisation as a default. CEZ Trading’s profile is heavily tied to Central European corridor dynamics but increasingly expresses itself in SEE through cross-border rights and regional desks. Slovenia’s HSE and Croatia’s HEP represent hybrid cases: both have meaningful physical assets, but their trading behaviour is increasingly shaped by intraday optimisation and the need to manage renewables volatility.
When you map these traders onto corridors, a consistent structure emerges. Corridors that link deep exchanges—such as those tied to Hungary and Romania—tend to be dominated by multi-hub and utility trading behaviour, where speed, access and margin compression matter. Corridors in the Western Balkans—especially those involving Montenegro and parts of Bosnia and Herzegovina—tend to be dominated by generation-anchored dynamics, where physical control and optionality matter more than micro-spread arbitrage. Greece sits between these regimes: it has enough volume to be a major price zone, but enough constraints to allow directional congestion rents to persist, which attracts both archetypes depending on the hour and season.
This sets up the industrial cost model. Industrial buyers rarely pay “spot.” They pay a delivered procurement price that can be decomposed into the index component plus a stack of risk costs. A simplified but realistic structure is an indexed supply contract priced as day-ahead or month-ahead reference plus supplier margin, plus balancing and profile costs, plus credit and regulatory risk buffers, plus sometimes cross-border congestion embedded indirectly in the supplier’s hedge cost. In a liquid market, the supplier can hedge cheaply and rebalance cheaply. In a thin market, the supplier hedges expensively and rebalances expensively, and those costs appear as premiums.
The crucial point is that trader density directly reduces those premiums. A market with many active traders compresses spreads and increases intraday depth, which lowers the supplier’s cost to hedge and correct. A market with few active traders has wider spreads and thinner intraday depth, which increases hedge cost and imbalance cost. The industrial buyer experiences this difference as a higher margin even when the index is the same.
A quantified scenario makes the effect tangible. Consider a constant-demand industrial facility with 50 MW average load, operating 8,760 hours per year, consuming approximately 438,000 MWh per year. Suppose the facility is in a mid-tier SEE market where suppliers price contracts as a day-ahead index plus a risk stack. In a thin-market baseline, it is common for the supplier’s total premium stack—margin plus balancing and risk—to be €8–12/MWh. In a more liquid, coupled market with deep intraday participation, that premium stack typically compresses toward €3–5/MWh. The difference is €5–7/MWh.
For this 50 MW facility, a €5/MWh reduction is worth roughly €2.19 million per year. A €7/MWh reduction is worth roughly €3.07 million per year. That is the annual competitiveness value of liquidity for a single medium-large industrial site. Multiply across dozens of large buyers in Serbia, Croatia, Bulgaria, Greece or Romania and the macroeconomic stakes become obvious.
Now consider the incremental effect of adding one additional fast, multi-hub trader into a thin or mid-liquidity zone. The mechanism is not that one company “lowers prices.” The mechanism is that it increases bid-offer depth and intraday corrective capacity, which reduces the supplier’s expected imbalance costs and hedging slippage. In practical SEE conditions, if the entry of one additional active trader increases intraday liquidity by 10–20% and reduces the average bid–ask spread by even €0.5–1.5/MWh on the products most relevant to suppliers’ hedge activity, the industrial buyer can see a delivered price improvement of €3–6/MWh depending on how concentrated the supply market is.
On the same 50 MW facility, a €3/MWh improvement equates to €1.31 million per year. A €6/MWh improvement equates to €2.63 million per year. This is why the identity of traders active in a market matters. It is not a marginal detail. It is a cost variable.
When you overlay corridor congestion, the trader influence map becomes even clearer. On borders where capacity is scarce and directional, traders with cross-border rights can monetise the spread. But that monetisation also accelerates convergence whenever capacity is available. In other words, traders profit from congestion, but they also reduce its duration. Where trader participation is limited, congestion rents persist longer and become effectively “paid” by local consumers in the form of higher time-weighted prices and higher supplier risk premiums.
GEN-I’s impact is strongest in precisely those environments where access and coupling allow fast convergence. It does not eliminate scarcity, but it converts it into a shorter, sharper event rather than a prolonged divergence. EFT’s impact is strongest in environments where physical optionality is decisive and where thin liquidity means the marginal exporter can shape the local curve. The utility traders provide the baseline liquidity, but they rarely compress spreads alone; they need the optimisation traders to do that job.
The industrial implication is that countries in SEE that want lower delivered electricity costs do not only need more generation. They need more market density: more participants, more intraday depth, and better cross-border access. That density is built by encouraging the entry and activity of professional traders, simplifying membership, aligning market rules, and ensuring that balancing and settlement frameworks do not punish intraday activity.
A practical ranking emerges. Markets linked to Hungary and Romania tend to offer the lowest structural risk premiums for industry because liquidity is deep and corridor access is broad. Markets in the Western Balkans without deep coupling tend to carry the highest risk premiums because thin liquidity and corridor constraints persist. Greece’s industrial pricing sits in the middle, heavily influenced by fuel-driven marginal pricing and congestion to neighbours. Croatia and Serbia are improving rapidly as their exchanges deepen, but their delivered industrial prices still reflect how often borders bind during peak hours.