bitbank

Is bitbank safe?

bitbank is one of the safer exchanges in Japan, and Japan is one of the safer places to hold crypto on an exchange. We found no theft from its wallets since it opened, its annual accounts are audited by Deloitte Tohmatsu and published, and Japanese law keeps nearly all customer coins offline. The main marks against it are a 2018 order from regulators to fix how it segregated customer assets, and that it is licensed in Japan only.

We score bitbank 81/100, a little above bitFlyer (80) and Coincheck (77).

Who runs bitbank?

bitbank, inc. was founded in Tokyo in May 2014 and registered as a crypto-asset exchange on 29 September 2017, number 00004 on the Financial Services Agency's register, among the first exchanges registered under Japan's licence.

On 1 October 2026 SBI Holdings became its sole owner. bitbank bought back the shares held by the internet company MIXI and by Ceres, completing a deal announced on 25 June, and the head of SBI's own exchange, SBI VC Trade, joined its board. bitbank says nothing changes for customers. For safety the change is mostly positive: SBI is a large listed financial group, though it now owns two competing Japanese exchanges, and any merger would bring new terms to read.

Japan's custody rules

Japan's rules are among the strictest anywhere. The Cabinet Office Order on crypto-asset exchanges sets the main points:

• no more than 5% of customer crypto, by yen value, may be held in internet-connected wallets; the rest must be offline or under equivalent controls;
• coins kept in hot walletsHot walletA crypto wallet connected to the internet, such as an app or an exchange's online wallet. It is convenient, but more exposed to hacking.More in the glossary must be matched by the exchange's own coins held offline, so a hot-wallet theft can be repaid;
• customer coins and cash must be kept apart from the company's own, and that segregation must be audited by an accountant at least once a year.

bitbank says it segregates customer cash and coins from its own assets. Its own disclaimer is candid that if its business could not continue, it might not be able to return everything. That warning applies to every Japanese exchange.

One product sits outside this protection. bitbank's lending service (貸して増やす) lets you lend coins to bitbank for a yield. Lent coins become a loan to the company; at the end of 2025 bitbank's balance sheet showed ¥18.2 billion of borrowed crypto. If bitbank failed, that money would be an unsecured claim.

Audited accounts instead of proof of reserves

bitbank does not run a Merkle-treeMerkle treeA way to combine many records into one short code, so that each person can check their own record is included without seeing anyone else's.More in the glossary proof of reservesProof of reservesA report in which a crypto exchange shows that it holds enough coins to cover all customer balances, ideally checked by an outside firm.More in the glossary. It does publish its balance sheet and income statement each year, with Deloitte Tohmatsu's audit opinion. The 2025 figures:

Deloitte is a Big Four firm, which counts for more than a crypto-native attestation. The thin equity, ¥12.8 billion against ¥605 billion of assets, is normal for an exchange whose balance sheet is mostly customer money, and it is now backed by SBI.

The 2018 business improvement order

On 22 June 2018 the Kanto Local Finance Bureau ordered bitbank to fix weak internal controls after an on-site inspection that began in April; bitFlyer, QUOINE, BTCBox and BITPoint Japan received orders the same day. The bureau found that bitbank had put growth first, that its internal rules did not match how it actually worked, and that customer cash it held often fell below the balances on its books. The order covered management oversight, segregation of customer assets, anti-money-launderingAnti-money launderingThe rules and checks that stop criminals from moving illegal money through banks, payment firms and crypto exchanges.More in the glossary controls, oversight of white-label partners and outsourcing, system risk and the listing of new coins, with an improvement plan due by 23 July 2018. bitbank said customer assets were not affected. We found no later regulatory action, but the segregation finding is why legal record scores 75 rather than in the 80s.

How to use bitbank more safely

1. Set up a passkeyPasskeyA way to sign in without a password. Your device holds a key tied to one website or app and unlocks it with your fingerprint, face or PIN.More in the glossary, as bitbank now recommends, and avoid syncing it to a cloud account you have not secured.
2. Reach bitbank only through its app or a saved bookmark; fake sites and impostor social media accounts are the common route to stolen logins.
3. Think before using the lending service. It pays a yield because your coins leave the segregated pool.
4. Keep long-term holdings in your own wallet. Japanese rules make exchange failure less damaging, not impossible.

How we scored it

Security history (88) is bitbank's strongest factor, with no known theft. Custody (82) and reserves (78) reflect Japan's cold-wallet and segregation rules and Deloitte-audited accounts, with deductions for the lending service and no proof of reservesProof of reservesA report in which a crypto exchange shows that it holds enough coins to cover all customer balances, ideally checked by an outside firm.More in the glossary. Licensing (75) and legal record (75) are the weakest: one country, and a 2018 order that touched segregation.