Crypto exchanges tout cold storage ratios after Binance attack

Crypto exchanges were quick to reassure users following the attack on Binance's hot wallet infrastructure last week, with several companies disclosing how they divide assets between cold storage and internet-connected hot wallets this week.

Crypto exchange Gate on Thursday launched a “Proof of Security” (PoSEC) framework, reporting that 88.26% of its total assets were in cold storage and 11.74% in hot wallets. It claims its cold storage could cover 104.58% of customer assets even if its hot wallets were completely drained.

“By publicly disclosing the distribution of assets between platform cold storage and hot wallets, PoSEC provides visibility into asset storage structures and their ability to cover potential losses under extreme scenarios,” Gate said. It noted the data is still undergoing independent review by a third-party audit firm.

Threat actors attacked Binance's hot-wallet infrastructure last week, stealing approximately $6.36 billion, most of it in about 20 minutes, according to TRM Labs. Binance CEO Richard Teng said the “vast majority” of user assets are held in cold wallets, but the company has not provided a precise split.

Other crypto exchanges have been quick to share their cold storage ratios this week.

Coinbase says 99% of customer assets held in cold wallets

In a blog post Wednesday, Coinbase said that more than 99% of customer assets are held in offline cold storage and that it continuously rebalances excess assets to cold storage.

“Binance's reported hot wallet incident has understandably left customers asking how Coinbase protects customer assets from something similar happening here,” it said.

On Tuesday, Upbit, the largest cryptocurrency exchange in South Korea, confirmed it holds 99.17% of its assets in cold wallets, with the remaining 0.83% in hot wallets as of September 2026. These figures are already disclosed to the Financial Supervisory Service.

“This represents the highest cold wallet storage ratio among South Korea's five major KRW-based cryptocurrency exchanges and is substantially above the regulatory minimum of 80%,” a spokesperson for Upbit parent company Dunamu told Cointelegraph, in response to questions about South Korea's call for crypto exchanges to increase their cold storage ratios.

“Our aim is to keep our hot wallet holdings at an absolute minimum, with a target of maintaining them below 1% of customer digital assets,” they added.

Other major South Korean exchanges have reported lower cold-wallet shares. Financial Supervisory Service figures cited in earlier reporting put Bithumb at 94.76%, Coinone at 85%, Digital X, formerly Korbit, at 82.79%, and GOPAX at 80.54% at the end of September.

OKX's existing security overview, last updated on Sept. 18, 2026, said it holds more than 95% of client crypto assets in cold wallets and less than 5% in hot wallets.

The reported ratios are not necessarily directly comparable because exchanges use different reporting periods and may calculate cold-storage shares against different asset bases.

Cold storage ratios, however, offer only part of the picture of an exchange's security.

Offline wallets can still be exposed through compromised signing systems, inadequate access controls or employees approving fraudulent transactions.

Hong Kong's Securities and Futures Commission warned in an August 2025 circular that such weaknesses could compromise both hot- and cold-wallet infrastructure.