Mikhail Fridman increased his investment in the store via the fund LetterOne to 15%, then reached an agreement with the company to buy a further 10% of its shares, according to the National Values Market Commission (CNMV).
As a result, this Friday saw Día’s shares increase 1.05% in price, to €4.40 each.
Día’s board of directors stresses there is no intention on Fridman’s part to launch a takeover bid.
According to LetterOne, Fridman now holds 93.4 million ordinary shares through the fund, and the company has agreed to his buying a further 62.2 million.
The tycoon, who is Ukrainian but has Russian nationality, has a total wealth of US$16.2 billion (€13.2bn), according to Forbes magazine, making him one of the richest men in Russia.
His name has reportedly been linked to hacking operations said to have helped Donald Trump become US president, although as yet, neither Fridman’s involvement nor Russia’s backing has been confirmed.
Fridman is also said to be connected to the multi-national firm Zed+, which is under investigation by a court in Madrid for allegedly hiding funds, as he holds a percentage of its capital.
The billionaire also holds shares in the petroleum sector, the banking and telecommunications industries and was one of the founders of the Russian financial entity Alfa-Bank.
Día is one of the Ibex 35 – the 35 companies on the Spanish stock market with the highest capital.
It has 7,400 stores in Spain, Portugal, Argentina, and Brazil and earned €103.1 million in the first nine months of 2017 – a fall of 11.7% on the same period in 2016.