The São Paulo stock exchange, the most important in Brazil, plummeted at Monday's opening by more than 15% following the unexpected second-round victory of Luiz Inácio Lula da Silva in the presidential elections held this Sunday. Lula's re-election has not been well received by the markets, which expected a change at the head of the most populous country in South America and the entry of the ultra-conservative Jair Bolsonaro.