Crypto exchange Bitget said a security breach exposed $351.6 million on Thursday, while CEO Gracy Chen assured users that customer funds and the exchange’s cold wallets remained secure.

Chen announced the incident on X after blockchain researchers detected unusual transfers involving wallets linked to Bitget. She said unauthorized transactions had taken place through some of the exchange’s hot wallets.

Bitget also has a user protection fund containing more than $464 million, according to Chen.

The CEO said Bitget’s three-tier wallet architecture helped limit the incident to part of its hot- and warm-wallet infrastructure. Cold wallets, which keep key signing credentials separated from internet-connected systems, were not affected, she said.

Trading and deposits continued following the breach, while withdrawals were temporarily suspended as Bitget carried out a security review.

The exchange’s disclosure came after on-chain data and independent researchers flagged suspicious wallet activity. Early estimates suggested that about $183 million in digital assets had been transferred from wallets identified as belonging to Bitget.

Emmett Gallic, an analyst at blockchain intelligence firm Arkham Intelligence, said three Bitget hot wallets and one cold wallet were involved in transactions spanning several blockchains. The assets included ETH, BNB, AVAX and USDT0, which were subsequently moved into a single wallet address.

Gallic initially put the amount involved at approximately $178 million and later reported that additional assets were being transferred.

Chen said Bitget intended to release an incident report within 24 hours.

The breach highlights the different security roles of hot and cold wallets. Hot wallets remain connected to systems that process transactions and withdrawals, while cold wallets are designed to keep signing credentials isolated from online infrastructure.

If the full $351.6 million amount is confirmed, the Bitget incident could rank among the largest crypto hacks of 2026. The Liquid Network reported a $320 million hack earlier this month, although the attackers later characterized themselves as “white hat hackers.”

Bitget’s BGB token initially sold off after news of the incident emerged but recovered some ground by 22:10 UTC. BGB was down 2.9% at press time.

Bitcoin declined about 0.29% over the previous 24 hours, while ether fell 0.2%.

The report was updated Sept. 24, 2026, at 22:10 UTC to add market reaction and at 22:05 UTC to clarify the description of the exploit.