BTC++ (ERC-20) is a synthetic Bitcoin asset generated by PieDAO through the collateralization of a basket of Bitcoin-pegged tokens (imBTC, pBTC, sBTC, and WBTC).
So far, PieDAO has released BTC++ and USD++. These are respectively a composition of multiple Bitcoin-pegged tokens (25% imBTC, 25% pBTC, 25% sBTC, 25% WBTC) and stablecoins pegged to the US dollar (USDC, TUSD, DAI, sUSD).
You can generate the corresponding BTC++ by staking your desired ratio of Bitcoin-pegged tokens on PieDAO, which helps mitigate the risk of illiquidity or malicious attacks on any single Bitcoin-pegged token. You can also trade BTC++ on decentralized exchanges like Uniswap.