Key facts
- Coinbase said more than 99% of customer assets are held in cold storage, offline from the internet.
- Coinbase said it keeps limited hot wallet balances to process customer deposits and withdrawals.
- Coinbase said its custody system combines offline storage with secure multiparty computation, which splits signing authority among participants.
- Coinbase's latest quarterly filing reported about $377 billion in platform assets, $8.6 billion in company cash and $2.2 billion in corporate crypto holdings.
- Coinbase said it holds customer assets on a 1:1 basis and does not lend or use them without explicit customer instructions.
- Coinbase estimated a 2025 incident, in which criminals bribed overseas customer support agents for customer information, could cost up to $400 million.
Coinbase said on November 4 that it was not affected by the $6.34 billion hack of a Binance hot wallet, and that more than 99% of its customer assets are held in cold storage rather than connected to the internet. The US exchange said it keeps limited hot wallet balances to process customer deposits and withdrawals while holding the bulk of funds offline.
In a blog outlining its security measures, Coinbase described distributed signing keys, withdrawal limits, unusual activity detection and controls that can halt transaction signing. It said its custody system combines offline storage with secure multiparty computation, which distributes cryptographic signing authority among separate participants so no complete private key sits in one location for transaction approval.
Coinbase said customers retain ownership of digital assets held through its exchange, with internal records tracking account balances and transactions. It said it holds customer assets on a 1:1 basis, does not lend or use them without explicit customer instructions, and keeps them separate from corporate funds. Its latest quarterly filing reported approximately $377 billion in platform assets, alongside $8.6 billion in company cash and $2.2 billion in corporate crypto holdings.
The protections apply to hosted Coinbase.com accounts; customers using the self-custody wallet remain responsible for securing their own private keys. Coinbase also points to regulatory oversight and independent SOC 1 and SOC 2 Type II examinations as part of its security framework, while saying these measures do not eliminate the possibility of a breach.
The reassurance follows the October 29 Binance incident, in which attackers reportedly accessed an internal wallet signing service and moved assets outside the exchange's normal withdrawal process. According to Binance, the attack began with a fake job interview that gave hackers access to employees' laptops, after which fraudulent withdrawal requests were submitted on October 29.
Coinbase said it develops its security software internally, unlike the external vendor systems reportedly involved in the Bybit and Bitget incidents. It has faced security problems of its own: in 2025, criminals bribed overseas customer support agents to obtain customer information, and the exchange estimated the incident could cost up to $400 million. Coinbase has also warned that artificial intelligence is giving attackers new ways to target employees, systems and customers.