South Korea’s privacy regulator has fined major crypto exchange Bithumb 210 million won, or about $136,000, over how it shared user data with an overseas partner. The case highlights how common trading practices, such as order book sharing, can still break strict cross‑border privacy rules.
Watchdog Says Bithumb Misled Users
The Personal Information Protection Commission (PIPC) announced the penalty after a plenary meeting on June 24. It said Bithumb “violated rules on the overseas transfer of users’ personal information” while working with a foreign exchange.
According to the regulator, Bithumb told customers that their data would be sent to the Australian Stellar exchange as part of a USDT market partnership. However, the investigation found the company actually sent member numbers and order details to a system operated by another platform, bingx.com.
The watchdog said that the mismatch broke South Korea’s Personal Information Protection Act, which requires clear notice and consent for overseas transfers. The commission also said Bithumb failed to meet all legal steps when it shared user information with 13 other foreign exchanges during asset transfers.
Order Book Sharing Triggers Privacy Rules
Order book sharing lets exchanges pool buy and sell orders so traders can match across platforms and see deeper liquidity. Yet the PIPC found that this technical link can count as an overseas data transfer if user identifiers accompany the orders.
In Bithumb’s case, the regulator said the company sent member IDs and order information abroad during order book sharing between September and November 2025. It concluded that Bithumb did not secure proper consent or follow all formalities for sending that data outside Korea.
Alongside the fine, the PIPC ordered Bithumb to fix its overseas transfer process and to update its privacy policy so users understand how their data might move across borders. The authority also released new blockchain privacy guidelines that urge firms to minimize the amount of identifiable information on public ledgers and to separate user identities from on‑chain activity whenever possible.
This privacy penalty lands as Bithumb already faces heavy pressure from other regulators. Earlier this year, the Financial Intelligence Unit fined the exchange 36.8 billion won over alleged anti‑money‑laundering failures in overseas transfers, the largest sanction ever issued on a Korean crypto platform.
Separately, Upbit and Bithumb both remain under scrutiny for whether their overseas order-book-sharing arrangements comply with consent and reporting rules.
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