BounceBit's own chain stopped producing blocks on 20 August 2026, shortly after an attacker moved a large amount of BB out of several accounts. It has not restarted.
The chain is being retired rather than repaired. BB is being reissued as a token on BNB Chain, using a snapshot of balances taken just before the attack, so the stolen tokens do not carry over.
That means your BB position continues, on a different chain, and your records need to follow it across.
What you get out of the box
Pick your import method.
Before you start
- Add your BNB Chain wallet. That is where BB is being reissued and where the position continues.
- Gather what you have from the old chain: exports, exchange statements, and anything showing what you originally paid.
On Kryptos
- Log in to Kryptos.
- Go to Integrations.
- Click Add Integration, then search for and select BounceBit.
- Click the BounceBit icon and choose Upload CSV.
- Upload the file. Kryptos reads it and categorises the transactions for you.
Good to know
- Balances were snapshotted just before the attack, so the reissued amount reflects what you held beforehand.
- BounceBit's own website still describes the chain as running. The chain has not produced a block since 20 August 2026.
- Assets other than BB that were on the chain may not be covered by the reissue. Check before assuming.
What happened, and what it means for your position
On 19 August 2026 an attacker exploited a flaw in the software BounceBit's chain was built on, one that failed to check whether an account had approved the movement of its funds. Around 286.5 million BB was moved out of nine accounts over the following hours. Block production stopped shortly afterwards and has not resumed.
BounceBit's response was not to repair the chain but to retire it. BB is being reissued on BNB Chain from a snapshot of balances taken immediately before the first unauthorised transfer, so the stolen tokens do not carry across and the accounts that lost them are made whole.
For your records, the important framing is that this is a migration rather than a windfall. You held BB before; you hold BB after; a chain in the middle was replaced. In most countries that continues your existing position and your original purchase price carries through.
The risk is that it will not look that way. Tokens arriving on BNB Chain with no matching outgoing transaction anywhere, because the chain they came from is frozen, is exactly what an airdrop looks like. Booked as income, it would tax the full value of coins you may have bought long ago, and leave the wrong cost behind for when you do sell.
Two smaller things worth knowing. The chain's history still contains the attack window, so a raw import will include movements that the snapshot voided. And the reissue covers BB; whether other assets stranded on the chain are being handled is not something we can confirm, so ask before assuming. For how migrations and losses are treated where you file, see the USA crypto tax guide or the UK crypto tax guide.
Where your Bitcoin really was
BounceBit's products were built on an arrangement worth understanding, because it changes what your deposit was in the first place.
When you deposited Bitcoin, it did not go into a contract you controlled or a wrapper you could unwrap yourself. It went to regulated custody firms, held in accounts those firms control. In return you received a token on the chain representing a claim on those assets, which you could then trade, stake and use as collateral like any other token. In some setups the custodied assets were also mirrored to an exchange so trading strategies could run against them.
That is a meaningfully different arrangement from wrapping an asset yourself. You gave up possession to a third party and received a distinct, freely tradeable instrument in return. Whether that counts as a disposal of the Bitcoin or as a deposit generating a receipt is a real question, and the answer varies by jurisdiction. We are not going to assert one, but anyone with a material position should raise it with an accountant rather than assume the conservative answer or the convenient one.
The receipt tokens also changed balance on their own as yield accrued, which is income arriving with no transaction behind it, and there could be several layers of them stacked on one deposit.
Manage your BounceBit portfolio with Kryptos.
Carrying your BB cost across the migration
The reissued token is the same holding under a new contract on a new chain. The price you originally paid should follow it rather than restarting.
Accounting for the deposit into custody
Assets placed into BounceBit's products were handed to regulated custodians in exchange for a different, tradeable token. That is not obviously a simple deposit.
Ignoring transactions that were reversed
The chain's history includes the attack window. Those movements are voided by the snapshot but still appear on chain.
Audit-ready, automatically.
Once your wallets and exchanges are connected, generating a tax report takes a single click. Open Reports from the menu, choose your jurisdiction, and download.
The reissue is a migration, not income
Receiving BB on BNB Chain to replace BB on the halted chain continues a position you already held. It should carry your original cost rather than being valued as a fresh airdrop on the day it lands.
It will look like an airdrop
Tokens appearing on a new chain with no matching outgoing transaction is the exact shape of an airdrop. Treating it as one would tax you on coins you had already owned.
Depositing Bitcoin here may not have been a simple deposit
Assets went to regulated custodians and you received a different, freely tradeable token in return. Whether that is a disposal or a deposit is genuinely arguable and depends on where you file. Worth asking rather than assuming.
Transactions in the attack window were reversed
The snapshot predates the attack, so movements after it do not count, even though they remain visible in the chain's history. An import reading the raw history will include events that were economically undone.
Rebasing tokens produced income without transactions
The custody tokens changed balance on their own. Those changes were receipts even though no transaction recorded them.
Read-only by design.
- A file upload is read-only. Nothing connects to your account
- Kryptos never asks for your password or login details
- Delete an import at any time and its data goes with it
- Keep the original file: it is your evidence if anyone asks later
If something doesn't sync.
The chain has not produced a block since 20 August 2026. Some endpoints still answer with that last block, which makes it look alive.
That is the reissue. It replaces what you held on the old chain, so it should carry your original cost rather than counting as new income.
Balances were taken from a snapshot just before the attack. Anything moved during the attack window is not reflected.
Still stuck? Email support@kryptos.io or open live chat from the app.