Coinbase says more than 99% of its customers’ crypto sits in cold storage, offline wallets that hackers cannot reach over the internet. It is the exchange’s answer to a $6.3 billion theft at rival Binance.
But Binance says its thieves never touched its private keys. They fooled the systems that approve withdrawals. Based on research, Coinbase holds 84% of US spot Bitcoin ETF assets.
Coinbase had $377 billion in assets on its platform at the end of September. It says that money belongs to customers, not the company.
“Coinbase does not lend or use those assets unless customers instruct us to.”
It also points to its S&P 500 listing and regular audits. Its US custody arm answers to New York’s banking regulator.
So how does it protect the funds?
Coinbase tracks the $377 billion apart from its own $8.6 billion in cash and $2.2 billion in crypto, per its latest quarterly filing.
Its New York custody arm is a qualified custodian and a fiduciary, bound by law to put clients’ interests first. In Europe, Luxembourg’s financial watchdog supervises Coinbase under the EU’s Markets in Crypto-Assets (MiCA) rules.
Coinbase says it was among the first crypto custodians to pass SOC 1 and SOC 2 Type II exams. Those audits check whether its security controls actually work.
Security chief Jeff Lunglhofer previously ran information security at BNY. His team of cryptographers and investigators comes from finance, national security, and law enforcement.
The attack began with a fake job interview, Binance said. Hackers then reached staff laptops and sent fake withdrawal requests on October 29.
BeInCrypto reported on November 1 that the Binance, Bybit, and Bitget thefts followed one pattern. Attackers tricked each exchange’s approval system into signing withdrawals. None stole a private key.
The report also weighed Coinbase’s security record against that pattern. Coinbase splits each private key into pieces stored on separate machines, a method called multi-party computation (MPC).
It also builds its security software in-house, while the Bybit and Bitget breaches came through outside vendors. Researchers argue that a stolen Coinbase laptop would yield only one useless key piece.
Why Hackers Hit Binance, Bybit & Bitget — Still Can’t Touch Coinbase: 🧵👇959K BTC. $103.31 Billion. 14 Years. 🔒1. No Giant Honeypot — 69.8M Separate AddressesMost exchanges pool billions inside a few live "hot wallets" for fast withdrawals.@coinbase doesn’t do that.… pic.twitter.com/aku0RReIbo
— Zeeme ⚡ | On-Chain Research (@0x_zeeme) November 1, 2026
Nevertheless, Coinbase has been hit before. In 2025, criminals bribed overseas support agents for customer data. The exchange estimated the cost at up to $400 million.
Its new post warns that artificial intelligence (AI) is changing how attackers work.
Users come to Coinbase to keep their money secure. We make sure that stays true.Secure custody is daily work for us, not a one-time achievement.That means 1:1 backing, >99% of funds in offline cold storage today, audited financials, key splits, no single points of failure and…
— Coinbase 🛡️ (@coinbase) November 4, 2026
Elsewhere, local media reported that South Korea’s Financial Services Commission urged exchanges on Monday to keep more than the legal 80% minimum offline. The Herald Business reported that Upbit already held 99.17%.
South Korea Considers Raising Crypto Exchanges' Cold Wallet Requirement to 99% Following Binance HackAccording to News1, South Korea’s Financial Services Commission is considering raising the minimum cold wallet storage requirement for crypto exchanges from 80% to around 99%… pic.twitter.com/PBZN8uVQng
— Wu Blockchain (@WuBlockchain) November 3, 2026
Notably, however, offline coins move slowly. Some Bithumb withdrawals were stuck for more than 13 hours in August when its online wallet ran dry, the Seoul Shinmun reported.
Korean exchanges warn that extra security staff will raise costs. Smaller platforms may not afford it, Newsway reported, leaving users with the biggest players.