Question:

Is there any Bitcoin-backed token?

Elijah: 25 May 2022

Is it possible to trade BTC and other altcoins on Ethereum's blockchain? If so, how?

Answer:
William: 25 May 2022

it is. You want BTCRelay. They spoke for a bit at devcon. It's essentially a means to utilize smart contracts to deposit and trade bitcoin.

http://btcrelay.org/