According to @MikeSilagadze, ether.fi card users have two days left as of Dec 21, 2025 to receive 10% cashback paid in ETH, source: @MikeSilagadze on X, Dec 21, 2025. The announcement specifies that rewards are denominated in ETH, linking the promotion directly to Ethereum (ETH) usage during the stated window, source: @MikeSilagadze on X, Dec 21, 2025. Traders focused on ETH-denominated rewards and on-chain spending incentives can note the time-bound nature of this offer as disclosed, source: @MikeSilagadze on X, Dec 21, 2025.