Upbit, Bithumb, and Coinone simultaneously suspended all deposits and withdrawals of the FLOW token, citing an urgent security review. The announcement was made on March 21, 2025, immediately impacting liquidity and market participant behavior.
Reasons for Suspending FLOW Operations on South Korean Exchanges
The exchanges issued nearly identical statements: they detected a potential vulnerability and initiated an investigation to eliminate risks to user funds. Meanwhile, spot trading of FLOW pairs remains available on order books, but token transfers to and from the exchanges are blocked until the review is complete.
Market Impact and Trader Reaction
The market reacted swiftly: FLOW’s price dropped about 7% following the announcement, and trading volumes for FLOW pairs on the affected Korean platforms fell by more than 60%. These figures indicate a sharp decline in short-term confidence among market participants in the South Korean segment.
At the same time, other global exchanges continued processing FLOW transactions, highlighting the localized nature of the restrictions imposed by the three Korean platforms.
Context and History of the Flow Blockchain
Flow is a proof-of-stake blockchain developed by Dapper Labs, designed for scalability in NFTs and gaming applications. Projects like NBA Top Shot and UFC Strike operate on the network, making it a significant ecosystem for digital collectible assets.
Previously, at the end of 2023, the Flow ecosystem experienced an incident involving a vulnerability in a smart contract on a third-party marketplace, resulting in a loss of approximately $500,000. This affected a third-party service rather than the core protocol, but it demonstrates that vulnerabilities in adjacent applications remain a real concern.
Regulatory Environment in South Korea
The South Korean Virtual Asset User Protection Act, fully effective since 2024, raises security and reporting standards for exchanges. Under these regulations, platforms must monitor and respond promptly to suspicious activity, which may explain the coordinated actions of the three major exchanges.
Similar practices—such as collective suspensions or coordinated security measures—have been observed among Korean exchanges in past instances when user and infrastructure risks arose.
Expert Analysis
Cybersecurity experts note that isolating an asset upon detecting anomalies or credible threats is a standard first line of defense, protecting hot wallets and preventing further spread of potential issues. Dr. Mina Choi from Seoul National University emphasizes this approach to blockchain incident response.
Exchange investigations typically cover the integrity of deposit address generation, known smart contracts, and network node software. Typical review durations range from 48 hours to two weeks, after which services either resume operations or implement necessary updates.
Why This Matters
For FLOW holders and active traders in Korea, the suspension means an inability to withdraw tokens and restricted liquidity access on local platforms, which has already impacted price and volumes. Even if you don’t hold FLOW, such events demonstrate how quickly exchanges can limit operations in response to threats and why monitoring official platform announcements is crucial.
Regulation and collective exchange measures increase the chances of protecting user funds but simultaneously raise short-term market uncertainty. This is significant for both international participants and local services working with related assets.
What to Do?
If you hold or trade FLOW on Upbit, Bithumb, or Coinone, monitor the exchanges’ official channels and avoid responding to third-party offers of "emergency withdrawals"—these are common phishing schemes. Remember: during the suspension, deposits and withdrawals are unavailable, but balances remain secure according to the exchanges.
If your workflow involves arbitrage or moving funds between exchanges, note that FLOW restrictions may disrupt strategies—carefully verify deposit/withdrawal statuses before transactions. For peace of mind, keep backup support contacts for the exchanges and rely only on official announcements.
Additionally, if you want to understand precedents and regulatory practices in Korea, check out the article on Bithumb deposit suspension, and for legal aspects, the article on South Korea’s digital financial security law is useful.
In Brief
Upbit, Bithumb, and Coinone halted FLOW deposits and withdrawals on March 21, 2025, due to an urgent security review; FLOW’s price dropped about 7%, and Korean trading volumes fell over 60%. Check official exchange statements and beware of scam offers during the incident.