Stocks in Helsinki showed a mixed performance today as investors reacted to surging oil prices due to an expected US-driven regime change in Iran and a cautious tone on Wall Street. The OMX Helsinki 25 was little changed overall in the afternoon, with gains in energy-linked names Neste Oyj and Fortum Oyj.

Among the Helsinki stock benchmark constituents, Neste, which refines oil and produces renewable fuels, was the biggest gainer with a nearly 7% surge today, benefiting from expectations of stronger margins amid tighter supply. Utility group Fortum also advanced as higher energy prices lifted sentiment.

A jump in crude supported refiners and utilities across Europe. Brent crude spiked sharply after military strikes and retaliatory attacks in the Middle East disrupted shipping through the Strait of Hormuz, a key route for global oil flows. Brent briefly climbed above $82 a barrel and was last trading near $77 in the afternoon, still up more than 6% on the day.

However, gains were tempered by a softer broader market backdrop. The S&P 500 slipped about 0.3% in early US trading, reflecting investor caution as geopolitical risks escalated. Even in Helsinki, telecom operator Elisa Oyj, elevator maker Kone Oyj, pharmaceutical firm Orion Oyj, and insurer Sampo Oyj edged lower, reflecting global equities under pressure.