U.S.-listed shares of Brazilian companies rose in premarket trading Monday as it became clear the incumbent Dilma Rousseff will face pro-business rival Aecio Neves in a second-round vote in Brazil’s most unpredictable presidential election since the nation’s return to democracy nearly three decades ago.

The runoff is set to take place on October 26.

Brazilian stock market: Neves’ surge

As reported, last week ISTO É magazine published the results of a survey by the Sensus polling company, which showed Ms. Rousseff gaining 37.3% of support, followed by 22.5% for Ms. Silva and 20.6% for Mr. Neves. The poll has a 2.2% margin for error which makes it a technical tie.

However, in an unexpectedly competitive runoff for Brazil’s presidency, Aecio Neves surprised analysts to take second place in presidential elections, forcing a runoff with incumbent Dilma Rousseff.

Aecio Neves draws his support from voters with higher incomes and more education. He has pledged to curb inflation that’s above the midpoint of the government’s target and said he would name former central bank President Arminio Fraga as his finance minister to regain investor confidence.

Dilma Rousseff, on the other hand, gets most of her backing among lower-income families, and much of her popularity comes from her success in lifting millions of Brazilian out of poverty. However, in her term, she oversaw the slowest economic expansion for any Brazilian president in over two decades.

Brazilian Stock Market

Brazilian stock market: Investors enthused

Following Neves taking up second place in the presidential election, investors are boosting wagers on the chances of a new government that would bolster growth and rein in intervention in the economy. Andre Perfeito, the chief economist at brokerage firm Gradual Investimentos, said: “Neves is seen by the market as the best potential president because he would be able to take measures to boost growth”.

Mirroring the latest developments, Brazil’s benchmark dollar bond due 2025 rose 1.89 cent to 101.94 cents on the dollar. Itau Unibanco Holding SA (ADR) (NYSE:ITUB) (BVMF:ITUB4), Latin America’s biggest bank by market value, climbed 11% to $15.60 in early trading in New York. Banco Bradesco SA (ADR) (NYSE:BBD) (BVMF:BBDC4), the region’s second-largest lender, rose 10%.

Brazilian stock market: MSCI Brazil Index rises 8.6%

The  iShares MSCI Brazil Index (ETF (NYSEARCA:EWZ) rose 8.6% to $47.11 before the bell, on the back of heavy volume.

The latest exit poll results highlight a stunning fall for former environment minister Marina Silva, who in late August held a commanding lead in polling, but took just 22% in the exit poll. Both Silva and Neves offered more centrist economic approaches, such as central bank independence, more privatizations and the pursuit of trade deals with Europe and the United States. Opinion surveys indicate around 70% of Brazilians say they want change, and this was highlighted by the mammoth anti-government protests last year.

Deutsche Bank analysts including chief economist Robert Burgess said: “It is a surprisingly strong support for Aecio, and markets will likely react in a bullish way today. All eyes are now on Marina Silva, who stayed neutral in 2010 but could support Aecio Neves this time”.