BitGrail halted withdrawals after reporting a 17 million Nano shortfall

BitGrail, an Italian cryptocurrency exchange, suspended its platform on February 9, 2018 after reporting that internal checks had uncovered unauthorized transactions and a shortfall of about 17 million Nano, then traded under the symbol XRB. The exchange said deposits and withdrawals would stop while police investigated and said the other currencies it handled were not involved.

That announcement turned an exchange-custody problem into one of the largest digital-asset loss reports of early 2018. It also triggered an immediate dispute over whether the Nano ledger or BitGrail’s own software was responsible. On the evidence available on February 9, the shortfall and shutdown were established; the mechanism, timing of the outflows, identity of any perpetrator and recoverable amount were not.

The exchange report and the protocol response

The Nano Core team said BitGrail owner and operator Francesco Firano informed it of a loss from the exchange’s wallet on February 8, 2018. In its statement released February 9, the developers said their preliminary review found no double spending on the Nano ledger and gave them no reason to attribute the loss to the protocol. They instead said the problem appeared related to BitGrail’s software.

That was a preliminary, interested-party assessment, not an independent forensic conclusion. Firano and the Nano developers were already in conflict. The Nano team said Firano had suggested changing the ledger to cover the loss; it rejected that option as impossible and contrary to the project’s direction. The exchange’s notice, meanwhile, characterized the transfers as unauthorized and said a complaint had been filed with the competent authorities.

The competing statements mattered because a public network and a centralized exchange are different systems. A protocol can continue processing validly signed transactions even when an exchange’s accounting, withdrawal controls or key management fails. The absence of detected ledger-level double spending would therefore not explain who authorized the transfers or whether BitGrail’s customer database matched assets in its wallets.

Measuring the reported exposure

Contemporaneous coverage commonly valued the missing Nano at about $170 million. That was an estimate, not a cash loss fixed by a closing auction. It came from multiplying the reported 17 million units by a market price hovering around $10 during the period. Prices varied by venue and time, liquidity was limited, and liquidating such a large position could have produced a different realized value. No evidence available on February 9 established that $170 million had been sold, recovered or was legally owed at that dollar amount.

The broader market was rebounding from its early-February selloff. CoinMarketCap’s historical snapshot for February 9 recorded Bitcoin at $8,736.98, up 6.81% over its preceding 24-hour measurement window, with $6.78 billion in reported 24-hour volume. Those are aggregator observations at the snapshot time, not an exchange closing price or proof that the BitGrail announcement caused any market move. The contrast is still useful: a platform-specific solvency crisis surfaced while major crypto assets were recovering.

What the record established

By the end of February 9, users could not withdraw or deposit through BitGrail, the operator had reported a roughly 17 million Nano deficit to police, and the Nano team had publicly denied finding a protocol-level double spend. Those points were independently repeated in contemporaneous technology and Italian press reports.

What remained unknown was at least as important. Neither side had published a complete forensic accounting, police had announced no findings, and the exchange’s use of the word unauthorized did not itself prove an outside hack. The defensible event-day conclusion was therefore narrower than many headlines: BitGrail reported a major custody shortfall and stopped operating, exposing how exchange balances depended on the solvency and controls of a centralized intermediary even when the underlying ledger continued to function.