Upbit review: trading IOST on Korea’s biggest won market

Verdict: deep IOST liquidity, a bumpy compliance record

We score Upbit 7.5 out of 10 for IOST. On the market itself it is hard to beat. KRW-IOST is the second-largest IOST market in the world after Binance’s IOST/USDT pair, spreads are usually a fraction of a percent, the KRW trading fee is reported at 0.05%, and IOST withdrawals cost nothing. Upbit also pays the IOST 3.0 airdrop every month and posts clear notices whenever the network changes.

The score would be higher without the baggage. Upbit has lost money to hackers twice, in 2019 and 2025, and Korea’s Financial Intelligence Unit has fined and restricted its operator Dunamu over anti-money-laundering failures. It is also open almost only to Korean residents, so for many readers of this site it is simply not an option.

Upbit at a glance

Upbit is run by Dunamu, a Seoul company founded in 2012, and opened in October 2017. It is Korea’s largest won exchange by a wide margin. For IOST it matters even more than its size suggests: an account named dunamuiost holds roughly 30% of the IOST L1 supply, which shows how much of Korea’s IOST sits in Upbit’s custody. Our IOST tokenomics page explains how concentrated the top holders are.

KRW-IOST and BTC-IOST on Upbit

Upbit opened its KRW-IOST market on 25 July 2018 and added BTC-IOST on 26 November 2018. It supported the swap to the IOST mainnet in February 2019. Both markets trade with no warning or caution flags. The KRW book is where nearly all the action is; the BTC pair is a niche for people who already hold bitcoin on Upbit.

Depth is the headline. Upbit and Binance each handle roughly a fifth of global IOST volume, while Korea’s next venue, Bithumb, trades a fraction of Upbit’s amount and Coinone barely trades at all. In practice this means orders of a few million won fill close to the screen price. Korean prices can still drift from global ones, so compare with our live IOST price tracker and the IOST to KRW converter before a large trade.

IOST has been flagged on Upbit twice. On 18 November 2019 Upbit briefly designated it a caution asset after node instability halted transfers. On 13 January 2025 the Korean exchange body DAXA issued a call for caution over the IOST 3.0 plan to issue 21.32 billion new IOST. That was a notice to investors, not a formal warning designation, and IOST was never delisted. Our IOST 3.0 explainer covers what changed.

Fees

Upbit’s KRW-market trading fee is reported at 0.05% for both makers and takers, and 0.25% on the BTC and USDT markets. We could not confirm these rates on Upbit’s own fee page, so check them in the app. Won deposits are free and won withdrawals cost ₩1,000.

A worked example: buying ₩1,000,000 of IOST on the KRW market at 0.05% costs about ₩500 in fees. The same trade through the BTC market would cost about ₩2,500, plus the cost of buying the bitcoin first. For IOST, the KRW market is the obvious choice.

Deposits, withdrawals and network forks

Upbit moves IOST on the IOST mainnet (L1). We found no support for the BEP-20 IOST token, so do not send BEP-20 IOST from BNB Chain to an Upbit address. L1 deposits to any exchange need the memo shown on the deposit screen; Upbit’s exact memo prompt could not be confirmed, so read the screen carefully and send a small test first. Our guide to sending IOST covers memos, test transfers and recovery requests.

IOST withdrawals are free per Upbit’s public guide, which is unusual. Sending 50,000 IOST to your own IOST wallet would cost nothing on Upbit’s side.

Upbit handles network events transparently. For the go-iost v4.0.0 hard fork it paused IOST deposits and withdrawals from 21 October 2026 at 12:00 KST and reopened them by 26 October 2026, while trading carried on. After the November 2025 hack it reissued deposit addresses and reopened networks in batches from 5 December 2025, and IOST was in that batch. The lesson for any exchange: check the deposit and withdrawal status before you move coins, especially around upgrades.

The monthly IOST airdrop

Upbit takes part in the exchange half of the IOST 3.0 airdrop, a pool of 852.8 million IOST shared among exchanges in proportion to the IOST they held at the snapshot of 15 March 2025 at 09:00 KST. Upbit pays its share in 48 monthly rounds. The first was paid on 10 April 2025 and the 19th on 21 October 2026. Your amount is the pool, times Upbit’s share of exchange-held IOST, times your share of Upbit’s IOST at the snapshot.

You do nothing to claim. The IOST appears in your Upbit balance, and nobody will ask you to connect a wallet or send coins. Upbit also ran the Donnie Finance (DON) airdrops for IOST holders in 2021; DON was later delisted on Upbit and is now withdrawal-only. Our IOST airdrop guide explains the L1 claim route and how to spot fake airdrops.

Hacks, fines and licence status

Upbit has had two serious hot-wallet thefts. On 27 November 2019 about 342,000 ETH, then worth roughly ₩58 billion, was stolen; Dunamu covered it from its own funds. On 27 November 2025, one day after the Naver deal was announced, attackers drained about ₩44.5 billion in SOL, USDC and Solana tokens. Authorities suspect the Lazarus group, and Dunamu covered ₩38.6 billion of customer assets from reserves. No IOST was reported lost in either case.

Cold storage is reported at 98.33% at the end of October 2025, and Dunamu pledged more than 99% after the hack. Korea’s Virtual Asset User Protection Act, in force since 19 July 2024, requires at least 80% cold storage, segregated customer assets and reserves or insurance.

Compliance is the bigger worry. In February 2025 the FIU ordered a three-month restriction on crypto transfers for new customers over about 5.3 million KYC violations. In November 2025 it fined Dunamu ₩35.2 billion for AML failures. In July 2026 the Financial Supervisory Service opened sanction proceedings over the 2025 hack. Upbit was the first exchange registered with the FIU, in October 2021, but we could not confirm whether its three-year renewal has been approved. Treat that as an open question.

Dunamu and the Naver merger

On 26 November 2025 Naver Financial announced it would acquire 100% of Dunamu through a share swap valued at about ₩15.13 trillion. The deal has not closed. The swap date moved from 30 September 2026 to 31 December 2026, and a filing on 7 October 2026 moved it again to 31 March 2027, with the shareholder meeting set for 26 February 2027. Competition and financial regulators are still reviewing it. For IOST holders, the merger changes nothing day to day, but it adds uncertainty about future policy.

A frequent Korean search is "IOST Kakao". We found no official link between IOST and Kakao or its Kaia (formerly Klaytn) chain. Our IOST in South Korea page covers the local market, tax plans and the other exchanges.

How to buy IOST on Upbit

1. Verify your identity

   Complete Korean real-name verification in the Upbit app.

2. Link K Bank

   Connect a K Bank account in your own name and deposit won for free.

3. Buy on KRW-IOST

   Open the KRW market, search IOST (아이오에스티) and use a limit order for size.

4. Hold or withdraw

   Keep IOST on Upbit for airdrop rounds, or withdraw on the IOST mainnet for free. Our how to buy IOST guide covers other routes.

Pros and cons

Outside Korea?

Upbit is effectively closed to foreigners. A common route is to buy crypto with a card on CEX.IO, an exchange running since 2013, then send it to an exchange that lists IOST. Some coins on CEX.IO are restricted for South Korean users.

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Alternatives

Inside Korea, Bithumb is the only other IOST/KRW market with real activity, and Coinone’s book is too thin to rely on. Korbit and Gopax do not list IOST, and binance.com does not serve Korean residents. Outside Korea, the deepest option is Binance’s IOST/USDT pair, and Thai residents have Bitkub’s IOST/THB book. Compare every venue on our IOST exchanges page.

IOST is volatile even by crypto standards: it sits more than 99% below its January 2018 high and its sharp spikes in September and October 2026 retraced within days. Read is IOST safe? before you buy, and never put in money you cannot afford to lose.