Why is Petrobras stock plunging today?

Petrobras stock has plummeted 21.7% today, opening at $20.49 after Brazilian President Luiz Inácio Lula da Silva secured a surprising fourth term in the presidential runoff. The outcome, which caught financial markets off guard, saw Lula defeat Senator Flávio Bolsonaro by a narrow margin of 51.8% to 48.2%. The market's reaction reflects the aggressive positioning of markets ahead of Lula's victory, following Bolsonaro's initial lead in the first round.

Prior to the runoff, stocks had climbed 7% above their pre-runoff levels and the real currency was nearly 5% stronger against the US dollar, with interest-rate futures pricing in tighter public finances and lower borrowing costs under Lula's leadership. The loss of confidence in Bolsonaro's fiscal policies, who had been anticipated to focus on spending cuts, has led to a significant sell-off across Brazilian companies' stocks, including Petrobras, Itaú Unibanco, Banco Bradesco, Nu, and MercadoLibre.

The broader U.S. market remained relatively stable, with the S&P 500 gaining 0.3% and the Dow Jones adding 0.5%. Looking forward, Lula's administration faces the challenge of managing Brazil's debt growth while maintaining public spending, with investors questioning whether his cautious fiscal approach can lower borrowing costs without increasing lender concerns.

The political uncertainty remains high as Senator Flávio Bolsonaro has not conceded, and Petrobras awaits its production and sales report due October 28 and Q3 earnings on November 10.