What explains the Ibovespa shooting in September?
The strong rise of Ibovespa's 5.03% in September was driven mainly by the relief of U.S. inflation, which reduced pressure on global interest rates, and the robust performance of the Brazilian banking sector in the last trading session of the month.
According to consolidated data from B3 released by media outlets, the main index of the Brazilian Stock Exchange closed the last trading session of September (30) with a rise of 1.37%, reaching the 186,340.46 points. At the peak of the day, the index touched the 187,834.97 points. This movement of final pull consolidated the month of September as the best monthly performance of Ibovespa since January of 2026, when the index had registered an increase of 12.56%.
Com o resultado, o acumulado do terceiro trimestre de 2026 (3T26) fechou com uma valorização de 8,32%. The financial market attributes this change of mood to the softer external scenario, which allowed a consistent recovery of domestic assets that were being penalized by the scenario of high local interest rates.
How did the PCE of the EUA function as fuel for the Stock Exchange?
The August US Consumer Spending Price Index (PCE) in the United States fell below market expectations, reducing fears of further interest rate hikes by the Federal Reserve (Fed).
According to official data relayed by FactSet, the full PCE 0.3% rose in August, accumulating a rise of 3.4% in 12 months — below the projections of analysts, who estimated 0.4% in the month and 3.7% in the year. The core of the indicator, which disregards the most volatile food and energy prices, advanced 0.2% in the month and reached 3% in 12 months, also below market estimates (which were 0.3% and 3.3% respectively).
For Rebecca Nossig, equity strategist at Nomad, this data was the great watershed for the robust performance of the Brazilian market at the end of the month, bringing direct relief to monetary policy expectations in the EUA. In the same vein, Pedro Fontes, research analyst of the Bitcoin Market, pointed out that the PCE brought the kind of surprise that the risky asset market needed, reducing the pressure on American long interest rates that had been rotating at historically high levels.
This environment of greater global liquidity and less risk aversion has also boosted cryptocurrencies. Bitcoin (BTC) has once again surpassed the US$ mark of 85 thousand, accumulating high of over 1.6% soon after the release of the American economic data, moving to record its best month of September since 2013.
What were the actions that led to the high of September?
The high liquidity banking sector and the companies most sensitive to the interest cycle were the main highlights of the quarter-end valuation, driven by solid balance sheets and foreign capital flows.
In the last trading of the month, the shares of large financial institutions registered significant jumps. The shares ITUB4 (Itaú Unibanco) and BBAS3 (Banco do Brasil) registered highs close to 5% (with advances of more than 4% consolidated in the session, according to data from Suno Notícias). Other industry roles, such as the BBDC4 (Bradesco) stock and the BBSA3 stock, also accompanied the strong upward movement.
In addition to banks, which have a relevant weight in the composition of the index, the relief in the interest curve opened space for the recovery of physical retail. The share MGLU3 (Magazine Luiza) shot more than 12% in a single day, reflecting the closing of sold positions and the search for domestic assets that were overly discounted.
| Ativo / Índice | Change in Day (30/09) | Acumulado em Setembro | Close (R$ / Points) |
|---|---|---|---|
| Ibovespa | +1,37% | +5,03% | 186,340.46 pts |
| Dólar Comercial | -0,81% | - | R$ 5,172 |
| Action MGLU3X Action MGLU3X Action | > +12,00% | - | - |
| Action ITUB4X Action ITUB4X Action | ~ +5,00% | - | - |
| Action BBAS3X Action BBAS3X Action | ~ +5,00% | - | - |
The dollar has fallen and futures interest rates have fallen: what changes to fixed income?
The decline in future interest rates and the fall of the dollar, which closed at R$ 5.172 with devaluation of 0.81%, bring a temporary relief for the risk premiums of long-term public bonds.
With the lesser pressure coming from U.S. Treasuries, DI futures contracts in Brazil showed mixed behavior, but with a relief bias on longer maturities. This move allowed inflation-indexed government bond rates, such as the long-term IPCA+ Treasury, to fall below the 7% level for the first time since May.
For those who invest in fixed income, this dynamic signals that the moment of maximum rates of mark-to-market may be finding a ceiling, although the domestic fiscal scenario and local political uncertainties still require caution in the allocation of very long deadlines.
Is it worth buying Stock Exchange now or optimism is transitory?
The recent valuation reinforces a neutrality thesis for Brazilian shares, where current prices already embed much of the local uncertainties, opening space for tactical repiques in high liquidity assets.
Despite the festive closing of September, market analysts recommend caution to the individual investor. Experts consulted by InfoMoney point out that, given the typical volatility of electoral periods and discussions about the fiscal target in Brazil, the ideal is to dedicate only a small portion of the portfolio to short-term tactical operations.
The safest strategy for the long-term investor remains the structural diversification of the portfolio, balancing defensive fixed income positions with shares of cash-generating companies that pay consistent dividends, avoiding trying to guess the "bottom of the pit" or the top of the market.
Attention: Past performance is not a guarantee of future profitability. The expressive September high reflects a technical adjustment to the external scenario, but domestic tax risks remain on investors' radar for the last quarter of the year.
