You can hold all Ethereum ERC-20 tokens in your wallet. These are tokens built on the Ethereum network.
You can find the full list at: https://etherscan.io/tokens
Why are some tokens excluded?
Argent is built on Ethereum because of the massive range of use cases it enables. This does though mean that we don't support tokens built on other blockchains.
Do you support Bitcoin?
No, we do not support it directly, for the above reason.
There are ways to get exposure to Bitcoin through Ethereum, for example WBTC. We'd recommend conducting your own research on which approach is best for you.
Tokens with the same name on different blockchains
Please be aware that some tokens have the same name but are on different blockchains. Only Ethereum-based tokens are compatible with Argent.
For example, Theta token was originally an Ethereum ERC20 token. But Theta has since launched their own blockchain, which also has a token called Theta. This new token is not compatible with Argent. The full list of compatible tokens can be found at: https://etherscan.io/tokens
For certainty please verify that that the 0x address on Etherscan and the 0x address of the token you are about to send are the same. If they don't match, your token is different from ETH token that Argent accepts and might be lost if sent to Argent.