Incident All ledgers
Ostium: $23.8m
Ostium lost $23.8m on 15 July 2026. Ranked 121st of 1,272 crypto failures, with method, returned funds and comparable incidents.
- Date
- 15 July 2026
- Lost
- $23.8m
- Returned or repaid
- None recorded
- Target
- DeFi Protocol
- Category
- Key Compromise
- Method
- Private Key Compromised
- Chains
- Arbitrum
Ostium, a perpetuals exchange on Arbitrum, lost about $23.75M on July 15, 2026 after an attacker used a compromised oracle private key to sign fake Bitcoin price reports, opening trades at false prices and closing them at market rates.
Against the ledger
- It ranks 121st of the 1,272 incidents with a known loss, and 16th in 2026.
- It accounts for 9.3% of the $254.7m in known losses in July 2026.
- 153 incidents in the ledger are classified as Key Compromise, for $8.96bn in total. This one is 0.3% of that.
- The ledger records no returned funds.
Closest in size by the same method
| Date | Target | Lost | Type | Method | Returned |
|---|---|---|---|---|---|
| 22 Jul 2026 | AFX Bridge | $24.1m | DeFi Protocol | Validator Key Compromised | — |
| 09 Jul 2018 | Bancor V3 | $23.5m | DeFi Protocol | Hot Wallet Key Compromised | — |
| 14 Apr 2023 | Bitrue | $23.0m | CEX | Hot Wallet Key Compromised | — |
| 04 Jun 2024 | Lykke | $22.4m | CEX | Hot Wallet Key Compromised | — |
| 29 Aug 2021 | Bilaxy | $21.7m | CEX | Hot Wallet Key Compromised | — |
All failures in 2026 · The failures ledger
Amounts are DefiLlama’s estimates and can change as incidents are revalued. Its returned figure can include money a company repaid itself, not only funds recovered from attackers. Source: DefiLlama.
Cite this Bitminer.io, “Ostium, failures ledger”, data to 2 November 2026, https://bitminer.io/ledger/incident/ostium-2026-07-15/. How this is built