Brazil’s main stock index, the Ibovespa, fell 17.3% in the week after Luiz Inácio Lula da Silva won the presidential runoff on October 25. It was a sharp example of how elections and financial markets interact, because for three weeks before the vote traders had been pricing a win for his opponent, Flávio Bolsonaro. By the Friday before the runoff, Brazilian stocks were almost 7% above their level before the first round, Reuters reported. Prices usually lean toward the likely result well before polling day, and the sharpest moves come when the count disagrees. With the US midterms on November 3, the same mechanics were at work in American markets in the run-up.
Quick answer: Elections and financial markets are connected through expectations. Traders weigh the chance of each outcome and what it could mean for taxes and spending, and prices settle between those scenarios before anyone votes. When the result matches what was priced, markets often move little. When it surprises, currencies and stock indices can reprice sharply in a single session.
Follow the Indices That React to Election Results
National stock indices often carry a large share of the reaction when a vote changes the policy outlook.
What Happened in Brazil’s Markets After the Runoff
Brazil’s runoff shows how elections and financial markets interact when the count goes against the price. Bolsonaro had unexpectedly finished first in the opening round on October 4. Markets read that as a sign of tighter public finances ahead, and Brazilian assets rallied for three weeks on the expectation.
| When | What markets did |
|---|---|
| Friday, October 23 | Stocks almost 7% above their pre-first-round level, and the real nearly 5% stronger against the dollar |
| Monday, October 26 | The dollar opened up 8.64% at 5.42 reais and closed up 8.21% at 5.40 |
| Monday, October 26 | Ibovespa futures hit their daily limit, and stock trading was halted for 30 minutes |
| Friday, October 30 | The Ibovespa closed at 167,922, down 17.3% on the week |
Figures from Reuters via Yahoo Finance, MercoPress, Trading Economics on the real, Al Jazeera and Trading Economics.
Rachel Ziemba of the Center for a New American Security told Al Jazeera that traders were “covering their bets that assume a Bolsonaro victory and tighter fiscal policy.” With public debt above 82% of GDP, the budget was the market’s main concern. Much of the sell-off was the unwinding of positions built over the previous three weeks.
How Elections and Financial Markets Price Uncertainty
Probabilities Come First
Traders treat an election as a set of possible outcomes, each with a likelihood. Polls and prediction markets both feed that estimate, and prices shift as it changes. A first-round surprise, like Bolsonaro’s, can reset the odds overnight.
Policy Is What Gets Priced
Markets care about the candidate mainly through policy. Government borrowing plans can move bond yields, and tax or regulation proposals can lift or weigh on particular sectors. Trade policy reaches further still, as our article on tariffs and trade wars shows.
The Result Is Only One Step
Uncertainty doesn’t end when the votes are counted. Reuters noted that investors in Brazil were already watching the choice of finance minister and the 2027 budget. A contested result adds another layer, and Bolsonaro had refused to concede when markets opened on the Monday.
Worked Example: Pricing Two Outcomes
Say traders expect a currency pair to settle around 5.00 if Candidate A wins and around 5.60 if Candidate B wins. They give A a 70% chance. A rough probability-weighted price is 5.18 (70% of 5.00 plus 30% of 5.60).
| Outcome | Where the pair goes | Move from 5.18 |
|---|---|---|
| Candidate A wins (expected) | 5.00 | Down 3.5% |
| Candidate B wins (surprise) | 5.60 | Up 8.1% |
Figures are illustrative.
That’s the basic arithmetic of elections and financial markets. The likely result produces the smaller move because most of it was already in the price. The less likely result produces a move more than twice as large, close in size to what the real did in October.
Many countries vote on a Sunday, when most markets are shut. A CFD position held into the result can open on Monday far from Friday’s close, and a standard stop loss then fills at the next available price. If the position uses leverage, the gap applies to the full position size, and leverage increases both gains and losses. Our risk management guide covers how traders size positions around events like this.
Uncertainty Can Be Priced Months Ahead
The link between elections and financial markets can stretch over many months. France’s next presidential election is due in spring 2027, and it’s already showing up in bond prices. On October 20, the gap between French and German 10-year government bond yields stood at 147 basis points, its widest since the eurozone debt crisis, according to Trading Economics, which pointed to fiscal worries and the coming election.
The Irish Times cited a report that Christine Lagarde’s early exit from the European Central Bank, announced on October 29, is meant to give EU leaders time to pick a successor before that vote. Political timing can feed into central bank planning, and through it into the euro.
What US Markets Are Pricing Before the Midterms
Republicans held 218 of the 435 House seats, according to the House Clerk, and 53 of the 100 Senate seats going into November 3. On October 20, prediction markets put a 63% chance on Republicans losing control of both chambers, according to The Motley Fool.
The Cboe Volatility Index, which tracks the volatility traders expect from the S&P 500 over the next 30 days, closed at 17.20 on October 29, according to FRED data. A reading under 20 suggests traders weren’t paying up heavily for protection against an election shock. That fits a market already leaning toward the outcome prediction markets favored, five days before the vote. A midterm can also carry less policy risk than a presidential race, because the president stays in office and the range of change to price tends to be narrower.
How to Read Markets Around Any Election
- The gap between polls and prices: a big lead in the polls that markets have already followed leaves less room for a move on the night
- Policy detail: budget plans and named ministers tend to move bonds and currencies more than campaign slogans
- Count timing: results that arrive over a weekend or across several days can create gaps when markets reopen
- Contested results: a refusal to concede can keep uncertainty in prices for longer
Elections and financial markets also meet in the forex market, where the currency is often the first asset to react. The forex trading page explains how currencies respond to changes in growth and policy expectations.
Key Takeaways
- Elections and financial markets are linked through expectations, which build up long before polling day.
- Prices tend to sit between the likely outcomes, weighted by their probability.
- An expected result often moves markets little, while a surprise can trigger a sharp repricing.
- Brazil’s Ibovespa fell 17.3% in the week after Lula’s October 2026 win, an outcome markets had priced as less likely.
- Weekend results can make prices gap at the open, and a stop loss may then fill at a worse price.
Frequently Asked Questions
How do elections affect the stock market?
Elections affect the stock market through the policies traders expect the winner to bring, such as tax and spending changes. Prices move toward the likely outcome before the vote. If the result is a surprise, stock indices can move sharply, as Brazil’s Ibovespa did when it fell 17.3% in the week after its October 2026 runoff.
Why does a currency fall after an election?
A currency can fall after an election when the result points to policies investors see as bad for public finances or inflation. The fall is usually largest when the outcome wasn’t expected. The dollar closed 8.21% higher against Brazil’s real on the Monday after Lula’s October 2026 win, an outcome markets had priced as less likely.
Do markets go down before elections?
Markets can rise or fall before an election, and volatility often picks up as traders protect against an unexpected result. How much depends on how close the race looks. Before the November 2026 US midterms, the VIX closed at 17.20 on October 29, a level that suggested traders weren’t bracing for a major shock.
What does it mean when an election is priced in?
An election is priced in when markets have already moved to reflect the outcome traders expect. If a candidate is widely expected to win, assets that would gain from their policies may rise beforehand. When that candidate wins, there’s little left to price, and markets often react only modestly to the result.