The Koinly article about staking describes what to do when you receive from pool more than what you have put there.
When you have sent a pair to pool, say x and y coins, and now you are receiving it back from the pool: it is clear what to do with the x coin that you now have extra, but my question is: In this situation the y coin amount has decreased, how to, or can it be deducted in taxes?
FAQ
How to handle reward payments that are received from the pool along with initial investment?
This is slightly more involved let’s say you sent 10 ETH into a pool and received 10.5 ETH back from the pool. If you were to mark the first transaction as Sent to Pool and second one as Received from Pool then you would see a missing purchase history error for the 0.50 ETH. You can resolve this by creating a manual Reward transaction in the Pool wallet right before the “received from pool” txn. We are working on making this easier to handle.