Coinbase stated Wednesday that it was not affected by the recent hack of rival exchange Binance, emphasizing that more than 99% of its customer assets are held in offline cold storage. The U.S.-based exchange outlined its security architecture in a blog post, asserting that its funds remain out of reach for hackers who drained approximately $6.4 billion from Binance’s hot wallets last week.
Offline Storage and Access Controls
Coinbase said it keeps the vast majority of customer assets in cold storage, defined as offline wallets that cannot be accessed via the internet. The company explained that private keys for these cold wallets are split into multiple pieces and are never fully reassembled, even during transaction signing. This structure is designed to ensure that stolen credentials, such as passwords or session data, cannot be used independently to compromise funds.
The exchange further detailed that no single employee has standing access to its hot-wallet signing service. Sensitive actions require multiple approvals, and strict limits cap the speed at which funds can move from cold to hot wallets. Coinbase noted that unusual withdrawal spikes are held for staff review, and the platform retains the ability to trigger “kill switches” that take signing keys offline entirely.
Recent Security Incidents
While asserting its resilience against the Binance attack, Coinbase acknowledged other recent security challenges. In May 2025, the company disclosed that criminals had bribed overseas customer support agents to steal personal data from less than 1% of its monthly transacting users. The attackers subsequently demanded a $20 million ransom, which Coinbase refused to pay.
Last week, Coinbase also reported a security incident involving analytics vendor Amplitude, which exposed contact data for a small subset of customers. The exchange clarified that customer funds were not affected by this third-party breach.
Asset Holdings and Market Context
Coinbase reiterated that customer assets are held on a 1:1 basis and are not lent out unless explicitly directed by customers. As of September 30, the company reported holding $8.6 billion in cash and cash equivalents, with $377 billion in assets on its platform.
The statement comes as investigators track the aftermath of the Binance theft. The FBI has attributed the hack to North Korea’s TraderTraitor group. Blockchain analytics firm Elliptic found that the laundering operation spanned approximately 12,000 wallets in under four days, while stablecoin issuers have frozen about 44% of the stolen funds. Coinbase identified artificial intelligence as a fast-changing security threat in its latest assessment.
