What is a token bridge?

A bridge allows token holders to use tokens from one blockchain on another. It differs from a migration in that the tokens on the first blockchain can still be used as they are. Currently you can bridge your WMTx between different EVM chains.

When will the Cardano WMTx to EVM WMTx bridge be live?

You will be able to bridge WMTx from Cardano to EVM chains soon. There is no official date for this so stay tuned.