Dear Cobo Users,

Cobo will support the upcoming Ethereum (ETH) L1 network upgrade and hard fork. In alignment with this upgrade, services for certain ETH L2 networks that rely on Ethereum L1 will also be temporarily suspended. The detailed arrangements are as follows:

· The network upgrade and hard fork are expected to take place at 05:49 on December 04, 2025 (UTC+8);
· Cobo will conduct maintenance on the ETH network starting from 04:50 on December 04, 2025 (UTC+8). During the maintenance window, withdrawal services for the ETH network will be suspended;
· Due to the impact of the ETH L1 upgrade, deposit and withdrawal services for the following ETH L2 networks will also be suspended:
- Arbitrum (ARBITRUM_ETH)
- Optimism (OPT_ETH)
- zkSync Era (ZKSYNC_ERA_ETH)
- Base (BASE_ETH)
- Manta Network (MANTA_ETH)
- Polygon (POL)
- Scroll (SCROLL_ETH)
- Plasma (PLASMA_XPL)
- Plume (PLUMENETWORK_PLUME)

Special Notice:
During the maintenance period, withdrawal functions for the above networks will be suspended. If users initiate deposit transactions during the maintenance window and the blockchain confirms the transaction, the corresponding crediting may be delayed. To avoid mis-deposits or unexpected asset inflows caused by on-chain operations, we recommend suspending deposits and related services for the affected tokens in your internal workflows.

We sincerely appreciate your understanding and cooperation. If you have any questions, please feel free to contact us.

Cobo Support
December 03, 2025