The Lisbon stock exchange was trading higher on Monday, driven mainly by Galp's shares, which soared by more than 20%.

By 8 . 20 this morning, the oil company's shares were up 20 . 17% to 19.275 euros, after the company announced a "potentially important commercial discovery" in Namibia.

On Sunday, Galp informed investors that the oil reserve in Namibia, in the first testing phase of the Mopane campaign, points to a "potentially important commercial discovery".

In a statement sent this Sunday to the Portuguese Securities Market Commission (CMVM), the company explains that "in the Mopane complex alone and before drilling additional exploration and appraisal wells, estimates of hydrocarbons at the site are 10 billion barrels of oil equivalent or more".

Three industry sources told Reuters that Galp is already trying to sell a 40% stake in the exploration block.

Galp holds an 80% stake and is operator in Petroleum Exploration License 83, which covers an area of almost 10,000 square kilometers in the Orange Basin. NAMCOR and Custos each have 10%.

Galp declined to comment, but had previously indicated that it might launch a process to attract other investors to its projects in Namibia, as these could reach a large scale.

Historic rise: even the stock market couldn't ride the wave

Thanks to the important discovery, Galp is preparing to close the best session in 17 years, only surpassed by the 24.7% gain recorded on November 9, 2007, according to data from Refinitiv cited by the ECO newspaper. The shares are trading close to their all-time high of €19.5.

The fluctuations were such that the shares were even suspended by the stock exchange mechanism that is triggered when there are large fluctuations.
Galp's shares were followed by those of BCP, Sonae and Jerónimo Martins, which advanced 2.27% to 0.31 euros, 2.21% to 0.92 euros and 1.24% to 18.00 euros.
Altri, Ibersol and Navigator shares rose 1.20% to 5.06 euros, 1.14% to 7.08 euros and 0.98% to 4.13 euros.
Shares in Mota-Engil, Corticeira Amorim and Semapa rose 0.76% to 4.22 euros, 0.62% to 9.77 euros and 0.39% to 15.32 euros. CTT shares were also up, namely 0.22% to 4.48 euros.

In the opposite direction, NOS shares led the losses and fell 8.06% to 3.31 euros.
The other three shares that fell were EDP Renováveis, EDP and Greenvolt, which recorded losses of 0.78% to 12.73 euros, 0.58% to 3.59 euros and 0.30% to 8.32 euros.