As of today, 5,446 tokenized BTC exist on Ethereum, across various types, worth approximately $51m. Tokenizing Bitcoin on Ethereum has generated a lot of buzz in recent weeks with the advent of new cross-chain variations like renBTC and tBTC, in addition to the inclusion of WBTC as accepted collateral for Maker. There are even new products like BTC++ from PieDAO, which essentially is an index token comprised of imBTC, pBTC, sBTC and WBTC at equal weightings, for the holder who wants to hedge their risk that any single variation might fail.
While these tokens can certainly be useful, it’s important to keep in mind that each has its own trade-offs regarding trust and security. These tokens are basically collateralized “IOUs”. In certain situations, like with WBTC, a holder needs to trust a federated group of entities and BitGo, a centralized custodian. In other situations, like with renBTC, a holder needs to trust that a decentralized, cross-chain network remains secure and well incentivized. These tokens will only maintain their price pegs to BTC if their underlying collateral is kept safe and the process to redeem is not overly burdensome.