During the snapshot, ARTH v1 holders had the option to deposit ARTH v1 into a "debt pool" (which was a pool which would promise to pay ARTH v1 holders their ARTH for a value of 1$) or swap their ARTH tokens to the ARTHX token.
Post the protocol launch, the swap and the ability to deposit into the debt pool was closed and existing holders saw a ~90% rebase for the ARTH v2 tokens to be backed by 110% worth of collateral.
I missed all this information. What can I do?
We understand that sometimes it's not easy to keep track of things.
If you are looking for your missing tokens, you'll find your address in the snapshot sheet linked above and you'll find that your address is airdropped with new ARTH v2 tokens on polygonscan.com (note that the tokens have undergone a 90% rebase).
You also have the option to deposit into the debt pool and reclaim 90% of the rebased value however to that you'll have to contact the team/moderators individually and send all your pending ARTH balance to be added into the debt pool.