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Crypto exchanges tout cold storage ratios after Binance attack
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- DeepHorus
Crypto exchanges are disclosing cold-storage ratios after an attack on Binance’s hot-wallet infrastructure last week. Gate, Coinbase, Upbit and OKX published details within days. They aim to reassure users that most customer funds are held offline.
TRM Labs said threat actors stole approximately $6.36 billion from Binance’s hot wallets, most in about 20 minutes. Binance CEO Richard Teng said the “vast majority” of user assets are in cold wallets. Binance has not provided a precise split.
Gate on Thursday launched a “Proof of Security” framework. It reported 88.26% of total assets in cold storage and 11.74% in hot wallets. Gate said cold storage could cover 104.58% of customer assets if hot wallets were drained, though third-party review is ongoing.
Coinbase said Wednesday that more than 99% of customer assets are in offline cold storage, rebalancing excess assets offline. Upbit confirmed Tuesday that 99.17% of its assets were in cold wallets and 0.83% in hot wallets as of September 2026. Its parent Dunamu said this is the highest ratio among South Korea’s five major KRW-based exchanges and above the 80% regulatory minimum.
Other South Korean exchanges reported lower shares: Bithumb 94.76%, Coinone 85%, Digital X 82.79% and GOPAX 80.54% at September’s end, per Financial Supervisory Service figures. OKX’s security overview, last updated Sept. 18, 2026, said more than 95% of client crypto assets are in cold wallets. The ratios are not directly comparable because exchanges use different reporting periods and asset bases.
Cold storage offers only part of the security picture. Hong Kong’s Securities and Futures Commission warned in an August 2025 circular that compromised signing systems, weak access controls or fraudulent approvals could expose both wallet types. The Binance incident is likely to keep pressure on exchanges to disclose more detailed custody arrangements and pursue independent audits.
