• Binance and Polymarket reported potential security breaches on Thursday.
• Binance is investigating a possible hack, with over a billion in losses potentially at stake.
• Polymarket also temporarily halted trading after a suspected breach.

Two major trading platforms — Binance and Polymarket — were investigating security incidents on Thursday, with the former facing potential losses in the billions. There's no evidence the incidents were related.

Binance, the world’s largest cryptocurrency exchange by trading volume, said it was actively investigating reports of a "potential security issue."

In an update late Thursday, Binance said that its initial investigation suggested that the incident may involve a compromised development operations engineer's laptop. This allowed an attacker to access a service container and submit unauthorized withdrawal transactions.

"We have found no evidence of any wallet private key leak," the company added.

Binance said the estimated total impact is about $6.3 billion, and it has worked with its blockchain partners to freeze around $3 billion in assets so far.

"Binance will cover all losses," Binance said on X. "As a precaution, all deposits and withdrawals are temporarily suspended while our team conducts security checks, freezes funds, and works with law enforcement."

The company did not respond to a request for comment.

Binance founder and former CEO, Changpeng Zhao, said on X a hack seemed likely.

“User funds are safe! It does look like a hack on Binance,” Zhao wrote in a post on X. “I don't manage Binance anymore, but as a shareholder, I expect all user funds will be fully covered.”

Zhao expressed appreciation to Tether and Circle, issuers of cryptocurrencies traded on Binance, for quickly freezing funds.

Tether CEO Paolo Ardoino said on X the company froze more than $1.5 billion related to the potential Binance hack. Circle CEO Jeremy Allaire said the company froze over $800 million in connection with the incident and that it was coordinating with law enforcement.

Polymarket also reported a security incident

Also on Thursday, Polymarket, the world's largest prediction market by trading volume, temporarily halted trading after users reported unauthorized withdrawals.

The company said in a statement on X that one of its third-party providers was compromised and that the incident had been referred to law enforcement. It also said trading had resumed by 3 p.m. Eastern time.

A Polymarket spokesperson told Business Insider that the malicious activity occurred in the UK and that the company will reimburse affected users. The company was unable to confirm the amount that may have been stolen.

Polymarket's US exchange was not halted and did not appear to be affected.

A person familiar with the matter attributed the Polymarket hack to a compromised third-party provider called DebugBear, a web performance monitoring platform designed to help businesses optimize website speed. It's unclear exactly how Polymarket uses the platform.

DebugBear did not respond to a request for comment. The company said in an X post on Thursday that it was aware of a security incident and was treating it as a "top priority."

Billions of dollars in crypto assets were reportedly stolen in separate hacks targeting Binance and Polymarket, triggering a market selloff and raising fresh concerns over digital asset security worldwide.

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The cryptocurrency industry faced one of its most turbulent days this Thursday as reports of massive security breaches involving Binance and Polymarket triggered sharp market declines, widespread panic among investors, and renewed concerns over the security of digital asset platforms.

While Binance investigated what could become the largest cryptocurrency hack in history, Polymarket temporarily halted operations following a cyberattack linked to a third-party service provider.

RELATED: Artificial Intelligence Pioneers Call for International Body to Oversee Cybersecurity Standards

The crisis began when reports emerged suggesting that Binance, the world’s largest cryptocurrency exchange by trading volume, had suffered a major security breach. Initial estimates indicated that nearly $600 million in crypto liquidations occurred across exchanges within a single hour as traders rushed to reduce risk amid growing uncertainty.

We are working non-stop to resolve this issue. Binance will cover all losses.

As a precaution, all deposits and withdrawals are temporarily suspended while our team conducts security checks, freezes funds, and works with law enforcement.

We are working around the clock and will… pic.twitter.com/zufWJ6V05D

— Binance (@binance) October 30, 2026

As the situation unfolded, blockchain analysts reported that wallets allegedly tied to the attackers had received digital assets worth more than $5.5 billion. Later disclosures suggested that the amount associated with the incident could exceed $5.7 billion across multiple cryptocurrencies, including Bitcoin, Ether, USDT, and USDC.

The market reaction was immediate. Bitcoin fell below the $80,000 threshold, while Binance Coin (BNB), the exchange’s native token, dropped sharply. Other major cryptocurrencies also recorded significant losses as investors sought safety amid fears of a systemic security event affecting one of the sector’s most important institutions.

Changpeng Zhao, widely known as CZ and the founder of Binance, stated that the available information appeared to indicate that the platform had suffered a hack. Although no longer involved in the day-to-day management of the company, Zhao expressed hope that all customer funds would ultimately be protected.

Binance, for its part, sought to reassure users, stating that customer assets remained secure and urging the community to remain vigilant against scams and phishing attempts that often proliferate during high-profile security incidents. The company also temporarily suspended several Binance Alpha services, including CEX Buy Token, Alpha Instant, and predictive trading-related functions linked to spot wallet funds.

As investigators worked to determine the full scope of the breach, Binance announced that approximately $2.54 billion worth of assets had already been frozen through emergency security measures. The exchange emphasized that only verified information would be released as the investigation continued.

We are aware of differing figures circulating publicly regarding the amount frozen, including references to $1.8 billion.

For clarity, the current verified total frozen is $2.54 billion. This figure may continue to increase as our teams work closely with law enforcement,… pic.twitter.com/Kx68qptfXk

— Binance (@binance) October 29, 2026

The turmoil was compounded by a separate cyberattack targeting Polymarket, one of the world’s most prominent prediction market platforms. The company temporarily suspended trading operations for nearly an hour after identifying a security incident involving an external service provider.

According to reports, attackers may have exploited a vulnerability connected to DebugBear, a third-party performance and analytics tool used by the platform. The breach allegedly resulted in the theft of roughly $2.65 billion to $2.7 billion worth of cryptocurrencies from user wallets, making it one of the largest incidents ever reported in the prediction market sector.

Following the attack, Polymarket notified British authorities, as preliminary information suggested the operation may have originated from the United Kingdom. At the same time, users reported missing funds and emptied wallets across community channels, raising concerns about the broader implications of third-party software vulnerabilities within the crypto ecosystem.

Despite the disruption, Polymarket moved quickly to restore operations and pledged to compensate affected users. In public statements, the company promised to reimburse all verified losses, an effort aimed at restoring confidence and preventing a prolonged loss of trust among traders.

POLYMARKET HALTS TRADING AFTER HACKERS DRAIN USER FUNDS WITHOUT PASSWORDS OR SEED PHRASES

Attackers allegedly exploited users’ active sessions to sell their positions and withdraw funds directly through Polymarket’s own system.

The attack reportedly originated from a… pic.twitter.com/GJB7MTrBfH

— Bitcoin News (@BitcoinNewsCom) October 29, 2026

Security Under Fire

The dual incidents have reignited a longstanding debate over cybersecurity standards in the cryptocurrency industry. For years, exchanges and digital asset platforms have promoted increasingly sophisticated security systems, yet the scale of the reported losses at Binance and Polymarket suggests that even major players remain vulnerable to large-scale attacks.

If confirmed at the estimated levels reported by analysts and security firms, the Binance breach would surpass all previous cryptocurrency thefts on record, marking a pivotal moment for the digital asset industry. Combined with the Polymarket attack, the events of October 29 erased billions of dollars in market value, exposed potential weaknesses in platform security infrastructure, and highlighted the systemic risks that continue to accompany the rapid growth of the global cryptocurrency ecosystem.

The cyberattack has renewed warnings about cybersecurity protections, investor confidence and risks associated with the use of digital financial platforms.

As investigations continue, regulators, security experts, and investors alike will be watching closely to determine not only how the attacks occurred, but also what they reveal about the resilience of the crypto industry in an era of increasingly sophisticated cyber threats.

Security incident linked to performance-monitoring tool spurred platform to halt trading for about an hour

Polymarket temporarily halted trading on its international platform on Thursday because of a security incident that compromised a third-party provider, the company said.

Trading was paused for about an hour and resumed on Thursday afternoon. The company has promised to fully reimburse any affected traders.

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© Photograph: Bloomberg/Getty Images

© Photograph: Bloomberg/Getty Images

© Photograph: Bloomberg/Getty Images

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