Traders in Brazil got an unwelcome surprise at the end of July. B3, the country's dominant exchange operator, suffered its worst-ever market outage on July 31.
For over three hours that morning, nearly all live market information from the exchange was unavailable to traders. The outage hit during the morning session, disrupting month-end book closing and rebalancing.
Derivatives trading that day came to just 13.6 million contracts, less than half of July's daily average. Stock volume also missed the monthly mark, and trading in several highly liquid assets fell by more than half.
The cause is still unknown. B3 internally called the event unprecedented and said it couldn't process data from the prior session, which delayed the next day's opening.
The July 31 failure followed a smaller outage in August 2025, making it the second major interruption within a year. Over half a dozen people with knowledge of the situation say smaller glitches have become more frequent over the past 12 months.
These issues often involve missing files on client positions before and after trades, affecting both stocks and fixed income. Analysts blame the near-monopoly B3 holds over most Brazilian asset classes.
"In a monopoly, companies have fewer incentives to improve, and without that competitive pressure, change tends to happen more slowly, and the market can become complacent. More competition is always a positive," said Fernando Siqueira, who leads research at Eleven Financial.
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B3 describes itself as Latin America's largest exchange and the only Brazilian venue for stocks, commodities and futures. Its current structure dates to the 2017 merger of BM&F Bovespa SA and Cetip SA. That central role means any breakdown can ripple across Brazil's financial system, since the same company also handles much of the country's clearing and settlement work.
B3 says its system is more complex than other markets because it combines the trading business with back-office work and risk management for stocks, securities lending and derivatives. It says it treats any issue that could affect service predictability with urgent priority.
A 2022 rule change created an approval path for new exchanges through Brazil's securities regulator.
Base Exchange, a Rio de Janeiro startup backed by Abu Dhabi's Mubadala Capital, wants to run a stock exchange. About 200 people work at Base Exchange, and the company says Brazil's securities regulator is close to letting it run trading and clearing services, with plans covering equities, real estate funds, ETFs and securities lending.
A5X SA, partly led by former B3 executives, is building a derivatives exchange. It has roughly 200 staff, sits near Sao Paulo's Faria Lima financial district, and is waiting on the central bank to test its systems. A5X plans to connect with market participants next quarter and start with derivatives in 2027.
A5X co-founder and vice-president Karel Luketic said, "As robust as B3 is, we see an opportunity for the market to reach the next level."
B3 shares fell more than the Ibovespa this week. Even so, the stock is up about 16% for the year through Thursday, with dividends included, helped by strong first-quarter foreign inflows, while the Ibovespa is up roughly 9%.
B3 will announce second-quarter results Tuesday, the first under CEO Christian Egan. Analysts expect solid volumes despite cooled stock activity.
Technology spending tells you how seriously B3 takes this problem. The company has spent about 3% of yearly revenue on technology recently, down from a 5% peak.
B3 argues that capital spending alone isn't a fair gauge, since much investment is counted as operating costs. Total infrastructure investment last year equaled about 9.6% of revenue, up from 8.5% in 2021.
BTG Pactual's team, led by Eduardo Rosman, said the outage leaves B3's market position unchanged. The incident, the report says, "reinforces the importance of technology execution and operational resilience as the competitive landscape evolves."
For investors with money in Brazil, the market is only as reliable as the exchange behind it. The competition that could push B3 to improve won't arrive until 2027.
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