With Lido the number of stETH tokens in your wallet increases or decreases based on the performance of the protocol to reflect any rewards you may receive. Lido typically updates token balances on a daily basis. stETH is withdrawable on a 1:1 basis for ETH.
For example, if you initially hold 1 stETH and your share of stETH on Lido gets you 0.1 ETH in rewards over time, your balance would be expected to update to show that you hold 1.1 stETH.
For stMATIC, the amount of stMATIC you hold doesn’t change to reflect rewards. Rather, the amount of MATIC you can withdraw in exchange for your stMATIC updates according to a conversion rate where your stMATIC represents your proportional claim to MATIC on the Lido protocol. This conversion rate increases or decreases based on the protocol's performance to reflect any rewards you may receive. Lido typically updates the conversion rate daily.
For example, if you initially received 1 stMATIC when Lido’s conversion rate was “1 stMATIC = 1.1 MATIC” and your share of stMATIC on Lido gets you 0.1 MATIC in rewards over time, the conversion rate would be expected to update to “1 stMATIC = 1.2 MATIC”.
If you want to skip the manual calculations, you can easily check the amount of your rewards in the Stake section of MetaMask Portfolio, under the ‘Lifetime Rewards’ column.
You can exit your staking position by withdrawing or swapping your stETH and stMATIC. See our article for more information.